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NEWS | Jan. 14, 2021

Peru’s Transition to an Adversarial Military Justice System

By Lieutenant Colonel Daniel E. Schoeni, edited by Lieutenant Colonel Patrick Neighbors and Major Alex Dehner

Learning About the Water We Swim In:

AFSOUTH’s Role in Peru’s Transition to an Adversarial Military Justice System

We sometimes take for granted how well our justice system works and what it means to have a fully functional JAG Corps. Our partner nations do not have such a system or such a JAG Corps. They want what we have.
2 fish swimming
There are these two young fish swimming along, and they happen to meet an older fish swimming the other way, who nods at them and says, “Morning, boys. How’s the water?” And the two young fish swim on for a bit, and then eventually one of them looks over at the other and goes, “What the hell is water?”
– David Foster Wallace[1] 

What’s the Difference?

Our adversarial military justice system, one feature of our common law heritage, is exported around the world. Until recently, most countries had an inquisitorial justice system derived from the continental civil law tradition. Why the shift toward adversarial justice? What is it about our criminal justice system, both military and civil, that other countries have found so alluring? What do we have that they want?

If you’re like me you graduated from law school with a vague awareness that Britain and its former colonies use the adversarial system, whereas continental Europe and their former colonies mostly use the inquisitorial. But what’s the difference? That was something of a mystery to me until 2013 when I started teaching trial advocacy with the Defense Institute of International Legal Studies (DIILS) in Mexico. Its armed forces were transitioning to an adversarial system, and at first I had little comprehension of the inquisitorial justice system. It just didn’t make sense to this corn-fed Iowa lawyer. A better understanding came gradually as I taught a half dozen courses and, later, when I wrote two short articles to make sense of what I had observed.[2]

In 2017, I was assigned to 12 AF/JA (AFSOUTH). 12 AF is a Component Numbered Air Force, meaning that it serves two masters: Air Combat Command (ACC) at Langley AFB, Virginia, and U.S. Southern Command (SOUTHCOM) in Miami, Florida. Upon arrival, I learned that SOUTHCOM had assigned AFSOUTH the lead for legal engagements in three countries: Peru, Guatemala, and the Dominican Republic. A few months later, I found myself at a working lunch in Lima with senior Peruvian judge advocates discussing challenges with their transition to an adversarial system. I told them about my experience in Mexico, and they later invited us to model our upcoming subject-matter expert exchanges (SMEEs) on our program there.

We have since led two such SMEEs in Peru and a third was postponed due to COVID-related restrictions. During our first, the editor of the ministry of defense’s military justice law review, El Jurista, invited me to write an article explaining what we were doing and why. What follows is adapted with permission from that piece.[3]

The value of this article to the Corps is threefold: first, military justice practitioners may learn from the comparative analysis since gaining a deeper understanding about what distinguishes our system from others makes us better counselors and advocates; second, to those who serve in countries with inquisitorial systems (e.g., Japan, Korea, Turkey, Spain, Italy, Germany), it provides some perspective; third, to the 508 attorneys and paralegals who self-identify in Roster as proficient Spanish-speakers and want to use their language skills, it offers some suggestions for getting one’s foot in the door.

Those who study a foreign language often say that the experience helps them to understand the mechanics of their native language better. Before discussing Peru’s reforms, I discuss the adversarial system, contrast it with the inquisitorial, and explain why the U.S. government has for decades sought to replicate its system abroad. This analysis will, I hope, be useful both to JAGs stationed abroad and military justice practitioners in a similar fashion: this comparison may offer insights that are perhaps less obvious when our system is viewed in isolation. We are, in short, sometimes ignorant about the water that we swim in.

A common misconception is that the adversarial system originated in medieval England.

The Adversarial System

A common misconception is that the adversarial system originated in medieval England.[4] In fact, the system traces its roots a couple of millennia further back and is arguably more ancient than the inquisitorial system. While the inquisitorial system originated in imperial Rome, the adversarial system originated in ancient Greece and the early Roman Republic.[5] Like the modern variety, ancient adversarial systems were public and featured an oral contest between the parties (prosecution and defense). The inquisitorial system, by contrast, was secret, written, and the parties had passive roles — only the judge had a truly active role in the process. Eventually, the former was associated with democratic societies that subordinated state powers to individual rights and liberties, the latter with powerful governments that sought to control, subjugate, and impose order.[6]

The most distinctive feature of the two systems is the judge’s role: if the judge herself conducts the investigation and drives the process, the system is inquisitorial; if her rulings are based on facts and arguments presented by the parties, the system is adversarial.[7] This approach is not merely a structural or procedural nicety, but lies at the core of what makes the adversarial system different.[8]

There is another essential facet to America’s adversarial system. Our republic was founded on a political culture that mistrusted government, not just our own institutions but the very idea of government. Our criminal justice system reflects this fundamental suspicion and is thus mainly oriented to protecting individual rights.[9] The aphorism attributed to Blackstone says, “It is better that ten guilty people escape than an innocent suffer.”[10] This was also well known to the Founders[11] and constitutes a cardinal principle of our country’s legal system.[12]

When Latin American nations achieved independence in the first decades of the nineteenth century, their founders were aware of liberal justice systems such as ours. Their framers deliberately rejected such systems and chose instead the inquisitorial system because they distrusted jurors, public hearings, and oral advocacy.[13] They doubted that their people were prepared for a freer, more democratic system.[14] A century and a half later, public opinion swung in the opposite direction. Whereas the secrecy of the inquisitorial system was thought to be ineffective, bureaucratic, and associated with corrupt dictatorships, the more open adversarial system had become associated with freedom, democracy, and the protection of human rights.[15]

If the protection of individual rights is the hallmark of the adversarial system, we often associate the inquisitorial system with the horrors of the Spanish Inquisition.

The Inquisitorial System

If the protection of individual rights is the hallmark of the adversarial system, we often associate the inquisitorial system with the horrors of the Spanish Inquisition.[16] This is misplaced and is due not only to ignorance, but also in part to successful anti-Catholic propaganda of the Protestant Reformation.[17] The inquisitorial system is not synonymous with torture, brutality, or intolerance. Nor is it necessarily inferior to the adversarial system. Each system has its pros and cons and makes reasonable tradeoffs between order and liberty. However, having made that concession, this summary undoubtedly betrays my prejudices in favor of the adversarial system.

The most significant right of the adversarial system is the presumption of innocence. The inquisitorial system, by contrast, assumes that the accused is guilty.

The adversarial system is characterized above all by due process. That phrase is a term of art, and American law students spend many hours poring over the case law and coming to understand what that means. Due process covers a range of rights and structural aspects of our system, including a hearing, a jury composed of one’s peers, representation by counsel, an impartial judge, and procedures driven by the parties.[18] By contrast, the inquisitorial is characterized by an investigator-judge, whose prominent role includes not only charging the offense and directing the proceedings but also supervision of the investigation.[19] Instead of evidence being presented mostly through live testimony during a relatively brief trial as in the adversarial system, judges in the inquisitorial system assemble a dossier of written evidence, painstakingly collected over a longer period.[20]

The most significant right of the adversarial system is the presumption of innocence. The inquisitorial system, by contrast, assumes that the accused is guilty and is therefore much more comfortable with pretrial detention. This procedural distinction may seem minor, but it has resulted in the mass incarceration of Latin Americans awaiting trial[21] and in large measure explains the crisis of the inquisitorial system in the region.[22]

Most of Latin America is transitioning to the adversarial system. [23] This did not begin with a U.S.-led initiative, but with the pens of two Argentine scholars in the 1980s, Alberto Binder and Julio Maier.[24] Like-minded scholars throughout the region advocated for a transition to the adversarial system because, they argued, the existing system was susceptible to corruption and incompatible with democracy.[25] Such scholars were aware that the adversarial system had its own problems, but they nonetheless believed that public trials would better protect individual rights and be more efficient.[26] To persuade voters, they also emphasized that the new system would be more consistent with internationally recognized human rights norms. Their rhetoric resonated with the people, who had grown to distrust the inquisitorial system because of its association with authoritarian and repressive governments.[27] A wave of reforms ensued, and the consensus is that the resulting systems have been better aligned with human rights than their predecessors.[28]

Like-minded scholars throughout the region advocated for a transition to the adversarial system because, they argued, the existing system was susceptible to corruption and incompatible with democracy.

The Adversarial System’s Merit

Winston Churchill famously said that democracy is the worst form of government … except for all the others.[29] The same could be said about the adversarial system.[30] We should not fool ourselves. Our system is imperfect. We are always improving it, hoping to make it more fair, efficient, and reliable.[31] But it does work. We believe in it enough that we consider it worth sharing — perhaps not for others to copy it to the letter, but at least to serve as a model to be adapted to local conditions.

What, then, are the merits of the adversarial system? Apart from the fact that the system is ours, why do we believe it is special and should be transplanted? The answer depends on how one defines what is preferable.[32] Before answering these questions, limitations must be recognized in the evaluation and comparison of systems.

As we will see later on, several U.S. government agencies have been dedicated to exporting our justice system in the last three decades, yet the empirical results are mostly unknown.[33] Despite the vast resources invested to carry out the reforms,[34] very little attention has been devoted to the evaluation of this effort.[35] Data collected have focused on the volume of training, not on more relevant indicators for the evaluation of a penal system, such as the reduction of violence, efficiency of operations, or protection of rights.[36] It is also difficult to make a definitive comparison because there have been so many varieties of reforms in the region.[37] In addition, more time is needed to assess whether the changes to the adversarial system have been successful in the long term.[38] Thanks to the comparative studies of the Justice Studies Center of the Americas in Chile, perhaps we will soon know more about the progress of reforms throughout the region.[39] Meanwhile, because of the limited empirical evidence, discussion about the advantages of the adversarial system remains somewhat speculative.

Arguably, however, our system possesses three merits. First, it better protects the rights of the individual.[40] Second, it is more efficient.[41] Third, its results are fairer. [42] The latter merit is especially important because the perception of fairness, many would argue, is fundamental to the rule of law and a properly functioning society.[43]

If not all the merits can be verified, anecdotal evidence supports faith in Latin America’s adversarial reforms. For example, we know that pretrial detention was more common under the inquisitorial system and this practice has been reduced with adoption of an adversarial system. We also see improvements in procedural efficiency. Perhaps most importantly, transparency has increased because trials are now public. This evidence suggests that the adversarial system represents progress, even if it is not a panacea.[44]

Exporting the Adversarial System

Exportation of our justice system began with political fights between President Ronald Reagan and Congress. President Reagan sought to support the anti-communist government in El Salvador and Congress opposed military support due to high-profile assassinations by the U.S.-trained Salvadoran military.[45] A commission was assigned to look for another way to support our ally without supporting its armed forces. The recommendation was to invest in democratization efforts, including reform of the justice system. Such reforms concentrated on the prosecution of human rights violations and other high-profile cases.[46] The U.S. Agency for International Development initiated a program first in El Salvador and later in Guatemala and Colombia that would replace their inquisitorial systems with the adversarial system. Such efforts accelerated with the fall of the Soviet Union, when the government sought ways to continue cooperation with allies, but found that without the Cold War a unifying logic was lacking.[47] The government eventually settled on the fight against transnational crime.[48]

Over time, a program whose benign purpose was to assist partners in fighting crime transmogrified into a program that sought to remake foreign systems in our image.[49] Our reform efforts in Latin America roughly coincided with, and were aided by, the aforementioned scholars’ advocacy for adversarial reforms.[50] Eventually, this effort involved 38 countries spanning the globe.[51] What began with reformation of civilian criminal justice systems extended to the realm of military justice. With reason, former Attorney General Eric Holder observed in the context of this program that “the rule of law has become one of the largest exports in the United States.”[52]

The U.S. government has invested considerable treasure in reforming criminal justice around the world, but the questions remain: Was it worth it? Is our system transplantable? Or is it a fragile plant that can only flourish in its native soil? Critics argue the effort was a failure. Others claim the reforms were worthwhile because the adversarial system is superior, even if we can’t prove it.[53] For the present we cannot know which side is right. Assessing the results of this revolutionary experiment will require more time.

Peru began its most recent attempt to adopt the adversarial system in 2004.

Peru’s Military Justice Reforms

Peru began its most recent attempt to adopt the adversarial system in 2004, with the second wave of countries making such reforms.[54] Together with Mexico, countries in this second wave benefitted from lessons learned from the first wave of reformers in the 1990s and thereby achieved greater success.[55]

Some are skeptical about the reforms.[56] As is the case with these reforms specifically in Latin America, it is difficult to evaluate global reforms.[57] Yet Peru, at least, has seen some promising results.[58] Preventive detention is now the exception rather than the rule. Wait times for trials have been halved.[59] These achievements are remarkable and indicative of wider progress even if the final results are still pending.

Law schools are reluctant to discard centuries of experience with the inquisitorial system and struggle to train the next generation of students in an unfamiliar system.

As reforms progress across Latin America, we see certain patterns. Lawyers and judges tend to resist change[60] and to revert to the familiar old processes.[61] Resources designated for defenders are insufficient.[62] Practitioners need more training.[63] Law schools are reluctant to discard centuries of experience with the inquisitorial system and struggle to train the next generation of students in an unfamiliar system.[64] Such ongoing challenges may explain in part why Peru’s JAG Corps requested our assistance.[65]

Opportunities for Spanish-speaking JAGs and Paralegals

During my two years at 12 AF, we saw remarkable progress in Peru. Having left AFSOUTH, I’m increasingly concerned about continuity and carrying on this legacy. I care about our partner countries and want the mission to succeed. Fortunately, there is no shortage of Spanish-speaking attorneys and paralegals interested in security cooperation, international law, and travel opportunities. If you’re one them, may I offer a few suggestions?

Over the years I’ve noticed some patterns about JAGs who are selected for the two Spanish-coded billets, AFSOUTH/JA and ODC Madrid. Here are some tips:

  • First, sign up for the Defense Language Proficiency Test (DLPT) at your testing center. Earn a good score  (a 3 Reading/3 Listening or higher makes you competitive). You’d be surprised how few actually do that.
  • Second, consider applying for the Language Enabled Airman Program (LEAP), which pays qualifying Airmen, including JAGs, Foreign Language Proficiency Pay even if they are not in language-coded billets. This singles you out as someone who has maintained proficiency and gained valuable experience using your language in service of the Air Force mission.
  • Third, short of the permanent assignments in Tucson and Madrid, look for intermediate opportunities. These include teaching the rule of law course at the Inter-American Air Forces Academy at Joint Base San Antonio-Lackland, TX; volunteering for the New Horizons exercise, which deploys personnel to the AOR for 6–8 weeks to build hospitals or schools; and serving as adjunct on DIILS mobile training teams.
Two years working at AFSOUTH afforded 17 trips to various countries in the region.


My introduction to this track resulted from dumb luck. Until 2014, the Air Force filled a 6-month TDY to Colombia. When my college roommate was tagged, his boss vetoed that deployment and sent him elsewhere. I was second pick. Later work in Mexico was also serendipitous. Two years working at AFSOUTH afforded 17 trips to various countries in the region. By my lights, 12 AF chief of international law is, no exaggeration, one of the most rewarding jobs in the Corps.

We sometimes take for granted how well our justice system works and what it means to have a fully functional JAG Corps. Our partner nations do not have such a system or such a JAG Corps. They want what we have. They can see what JAGs bring to the fight. I’ve had an interesting career. Yet sharing best practices with such eager learners has doubtless been a highlight.



demonstrates a direct examination

AFSOUTH’s Mr. Craig Burton demonstrates a direct examination of “Mrs. Bear” (played by Major Barbara Algarin) from the children's story Goldilocks, Iquitos, Peru, 27 Feb. 2019. (Photo by U.S. Air Force Lieutenant Colonel Daniel Schoeni)


opening ceremony for a trial advocacy exchange in Cusco, Peru on 18 July 2018

Senior Peruvian judge advocate presents during the opening ceremony for a trial advocacy exchange in Cusco, Peru on 18 July 2018. AFSOUTH’s Mr. Craig Burton translates for the SOUTHCOM SJA, Captain Bill Dwyer. (Photo by Army Captain Aaron Contreras)

About the Author

Lieutenant Colonel Daniel E. Schoeni

Lieutenant Colonel Daniel E. Schoeni, USAF

(B.A., Brigham Young University; M.A./J.D., University of Iowa; LL.M., University of Nottingham; LL.M., George Washington University; Ph.D. candidate (ABD), University of Nottingham) is the Staff Judge Advocate at Creech AFB, Nevada. He is licensed in Iowa and the District of Columbia.


[1] Jenna Krajeski, This Is Water, New Yorker, Sept. 19, 2008, https://www.newyorker.com/books/page-turner/this-is-water, quoting Wallace’s 2005 commencement speech at Kenyon College.

[2] Daniel Schoeni, Teaching Trial Advocacy South of the Border: Helping Mexico Transition to an Adversarial Military Justice System, Iowa Law., Jan.-Feb. 2016, at 36; Seminarios de Juicios Orales, infra note 3.

[3] This article was published in Peru’s El Jurista in June 2019, and was entitled Seminarios de Juicios Orales entre Comando Sur de los EE.UU. de Norteamerica y el Fuero Militar Policial. The author acknowledges Mr. Craig Burton, Lt Col Steven Loertscher, Mr. Samuel Londono, Mr. Antonio Lopez, and Lt Col Jennifer Sanchez for their valuable feedback, both substantive and linguistic.

[4] See, e.g., Janet Ainsworth, Legal Discourse and Legal Narratives: Adversarial versus Inquisitorial Models, 2(1) Linguagem e Direito 1, 2 (2015). 

[5] James L. Bischoff, Reforming the Criminal Procedure System in Latin America, 9 Tex. Hisp. J.L. & Pol’y 27, 31 (2003).

[6] Id. at 31–32.

[7] McNeil v. Wisconsin, 501 U.S. 171, 181 n.2 (1991).

[8] John D. King, The Public Defender as an International Transplant, 38 U. Pa. J. Int’l L. 831, 837 (2017) (arguing that the most profound change with this transition is the transfer of power to investigate and present charges from the judge to the prosecutor).

[9] Id. at 892–893.

[10] 4 William Blackstone, Commentaries *352.

[11] Daniel Epps, The Consequences of Error in Criminal Justice, 128 Harv. L. Rev. 1065, 1080 (2015).

[12] Id. at 1068 (citing United States v. Greer, 538 F.2d 437, 441 (D.C. Cir. 1976)).

[13] King, supra note 8, at 839–840.

[14] Id.

[15] Id. at 841–842.

[16] Erin Creegan & Clare Hatfield, Creeping Adversarialism in Counterterrorist States, 29 Conn. J. Int’l L. 1, 5 (2013) (observing that for most Americans the inquisitorial system is synonymous with the torture that was emblematic of the Inquisition).

[17] But see Mauricio Duce & Rogelio Pérez Perdomo, Citizen Security and Reform of the Criminal Justice Systems in Latin America, in Crime and Violence in Latin America: Citizen Security, Democracy, and the State 69, 72 (Hugo Frühling, Heather Golding & Joseph S. Tulchin, eds., 2003) (reporting that torture was common to extract confessions during the late Middle Ages).

[18] Id.; Allegra M. McLeod, Exporting U.S. Criminal Justice, 29 Yale L. & Pol’y Rev. 83, 117 (2010).

[19] McLeod, supra note 18, at 116–117.

[20] Ronald F. Wright, Mexican Drug Violence and Adversarial Experiments, 35 N.C.J. Int'l L. & Com. Reg. 363, 370 (2010).

[21] María Gracia Andía, The Uphill Battle of Justice Reform, Americas Q. 50, 51 (Summer 2012).

[22] A Broken System, Economist, July 4, 2014.

[23] Ainsworth, supra note 4, at 3.

[24] Id. at 4.

[25] Id. (observing that these scholars produced a model penal code in 1988 that has influenced the regional reforms since then).

[26] McLeod, supra note 18, at 119.

[27] King, supra note 8, at 841–842.

[28] Andía, supra note 21, at 51; McLeod, supra note 18, at 119–120.

[29] Winston Churchill, Nov. 11, 1947, International Churchill Society, https://winstonchurchill.org/resources/quotes/the-worst-form-of-government/.

[30] King, supra note 8, at 834.

[31] Perhaps the best example of the failures of our system is that 99% of cases are resolved through declaratory agreements because oral trials are too expensive to administer. See McLeod, supra note 18, at 117–118.

[32] Ainsworth, supra note 4, at 5.

[33] McLeod, supra note 18, at 160.

[34] Id. at 119–120 (reporting that in the program’s first decade alone the United States spent more than $500 million in Latin America).

[35] Id. at 87–88. See also Brett J. Kyle & Andrew G. Reiter, Militarized Justice in New Democracies: Explaining the Process of Military Court Reform in Latin America, 47 Law & Soc’y Rev. 375, 380 (2013) (noting that few investigations have been published regarding reforms of military criminal systems of Latin American countries and therefore the field is ripe for such an effort).

[36] McLeod, supra note 18, at 134–139.

[37] Daniel Pulecio-Boek, The Genealogy of Prosecutorial Discretion in Latin America: A Comparative and Historical Analysis of the Adversarial Reforms in the Region, 13 Rich. J. Global L. & Bus. 67, 67–68 (2014).

[38] Bischoff, supra note 5, at 49.

[39] Steven E. Hendrix, Current Legal Trends in the Americas: USAID Promoting Democracy and the Rule of Law in Latin America and the Caribbean, 9 Sw. J.L. & Trade Am. 277, 310–311 (2002/2003).

[40] King, supra note 8, at 892–893.

[41] McLeod, supra note 18, at 94; Judging Latin America’s Judges, Economist, Aug. 2, 2018.

[42] McLeod, supra note 18, at 94.

[43] Ainsworth, supra note 4, at 6.

[44] Judging Latin American Judges, supra note 40.

[45] McLeod, supra note 18, at 100–101.

[46] Id. at 101.

[47] Id. at 103.

[48] Id. at 116–122.

[49] Id. at 126–127 (counting that Department of Justice officials who were sent abroad to assist with the prosecution of crime tended to export our criminal system, despite instructions from their superiors to the contrary).

[50] Id., at 119; Ainsworth, supra note 4, at 3–4; King, supra note 8, at 841–842.

[51] McLeod, supra note 18, at 84–86 (recounting the creation of the Office of Assistance & Development Training of the Foreign Prosecutor's Office in the Department of Justice in 1991, whose mandate was the training of foreign prosecutors and now works in more than 30 countries).

[52] Id. at 84.

[53] Id. at 146–153; Judging Latin American Judges, supra note 41, citing Luís Pasara, Una Reforma Imposible: La Justicia Latinoamericana en el Banquillo (2015); Paul Hathazy & Markus-Michael Müller, The Crisis of Detention and the Politics of Denial in Latin America, 98:903 Int’l Rev. Red Cross 889 (2016).

[54] Andía, supra note 21, at 50–51. In fact, Peru had already experimented with adversarial systems, first in 1924 and again in 1990. Id. at 52; Duce & Pérez Perdomo, supra note 17, at 74.

[55] Andía, supra note 21, at 50–52.

[56] See, e.g., Judging Latin American Judges, supra note 41 (citing an academic, Luis Pasara, who says that the reform has not diminished impunity nor increased public confidence).

[57] Bischoff, supra note 5, at 49.

[58] Andía, supra note 21, at 52.

[59] Ross Boone, Reform of the Criminal Justice System in Peru, Human Rights Brief (Mar. 27, 2014), http://hrbrief.org/hearings/ reform-of-the-criminal-justice-system-in-peru/.

[60] Andía, supra note 21, at 53.

[61] Judging Latin American Judges, supra note 41.

[62] King, supra note 8, at 865–866 (citing a study saying that the right to a defender is usually a formality, not a legal guarantee); McLeod, supra note 18, at 151–152 (reporting that defenders are insufficiently trained and their numbers are disproportionate with prosecutors).

[63] King, supra note 8, at 863–865; Bischoff, supra note 5, at 49–50; Judging Latin American Judges, supra note 41. See also The Honorable M. Margaret McKeown, The ABA Rule of Law Initiative: Celebrating 25 Years of Global Initiatives, 39 Mich. J. Int'l L. 117, 132 (2018) (noting that the transition to another system must be extremely difficult for lawyers with experience in the old system).

[64] Andía, supra note 21, at 53.

[65] McKeown, supra note 64, at 132–133 (describing the training program that Peru has developed to close the gap).