The fundamentals the Irish National Army used in the Irish Civil War (1922–23) are a model for the successful application of a classic counterinsurgency which, if understood earlier, could have made a difference in the United States’ most recent wars in Iraq and Afghanistan. John A. Nagl and Gareth Prendergast explain. 

Keywords: counterinsurgency, Ireland, Irish Civil War, military strategy, treaty

Stephanie Crider (Host)       

Welcome to Decisive Point. The views and opinions expressed in this podcast are those of the guests and are not necessarily those of the Department of the Army, the US Army War College, or any other agency of the US government.

I am speaking with Gareth Prendergast and John A. Nagl today.

Prendergast is a serving colonel in the Irish Army and the author of Clear-Hold-Build: How the Free State Won the Irish Civil War

Nagl is the General John J. Pershing Professor of Warfighting Studies in the Department of Military Strategy, Planning, and Operations at the US Army War College. They coauthored “Turning Tactical Victories into Strategic Success: Counterinsurgency in the Irish Civil War, 1922–23,” which you can find in the Summer 2026 issue of Parameters.

This podcast has been a long time in the making. Thank you both for showing up today.

John A. Nagl

Delighted to be here, Stephanie.

Gareth Prendergast

Hello, Stephanie.

Host

Let’s just start at the beginning. How did you two meet?

Prendergast  

I met John at a conference in, Ireland, well, 15 years ago. And, I’d heard all about him. I’d read his book. I bought him a pint of Guinness, and we were chatting at the bar for the evening in the officer’s mess. I felt we obviously made a connection. So, a few years later, when I asked him if he’d like to write the foreword to my book, he was very generous, and he said he would—but I had to invite him to Ireland and buy him a pint of Guinness.

So, I did that.

Nagl

That seemed reasonable to me. It seemed like a reasonable ask on my part.

Prendergast

Yeah.

So, I met him in Ireland, and he says, “Oh, you’re not the guy I remember. You’re a different person.” So…

But he still came all the way over to Ireland, and he still wrote the foreword to my book. And, I hope we’ve become good friends ever since.

And, I would like to thank him.

Nagl   

Yeah, Gareth and I have spent time together, both, on his island and, here in the United States. And, I was really honored to write the foreword to his book, which is another example of the basic principles of counterinsurgency being applied to a case that many people on this side of the Atlantic don’t know very well.

And, it illustrates, to me, the enduring value of the counterinsurgency doctrine that General David Petraeus, General Jim Mattis, [Dr.] Conrad [C.] Crane of our own Army War College, [and] a number of people wrote, now 20 years ago.

And, that continues to, I think, influence how—not just the American military, but a number of militaries around the world—think about this very challenging kind of war.

Host   

Why did you decide to write this article?

Prendergast  

It’s primarily from my book. And, I just wanted to highlight to people in America (and to a newer audience) the dangers, first of all, of a civil war and how you can blindly follow an ideology, or your leadership, as it happened in the Irish Civil War, into a vicious encounter—even though you don’t fully understand what you’re fighting for.

And, I also wanted to demonstrate how the clear-hold-build philosophy that was developed by the Americans during the Iraq conflict actually worked during the Irish Civil War. And, I thought the Irish Civil War, as John said earlier, would be a very good case study to study clear, hold, build.

And, when John offered to write an article with me, I [said], “Yeah, this would be fantastic to do it in such a prestigious magazine as Parameters.”

And it’s just a pleasure to be able to write an article with John Nagl.

Host   

Well, we’re delighted to have both of you in Parameters.

Nagl   

We are happy to be in Parameters.

Gareth is being modest, I think, which is a bit of the Irish one. First, his brother is a student here at the Army War College this year—his taller and better-looking brother. I think he’s the smart one, and his brother, John, is the good-looking one.

His book has done remarkably well in Ireland, and I think deserves more attention here on this side of the pond.

Prendergast

Thanks very much, John, for [those] kind words.

Nagl   

And, just a reminder that Ireland and America have both suffered from horrible civil wars. And, I think we have a great deal to learn from each other—from each other’s experiences and, the effort [required] to make sure that those sorts of horrors never happen again here, or in other countries, to the extent that we can.

Host   

A few minutes ago, Gareth, you alluded to the similarities between the Irish Civil War and conflicts in the twenty-first century. What makes this conflict, in your view, so relevant to the challenges faced by armies in the twenty-first century, particularly in places, as you mentioned, like Iraq and Afghanistan?

Prendergast  

I think one of the key elements of it is why the antitreaty IRA (Irish Republican Army) started the civil war over an ideology. John and I are both graduates of the US Army Command and General Staff College in Leavenworth, [Kansas], (and actually, John is a Marshall Award-winning graduate). But, one of the first things we learn over there is the Clausewitzian quote that no one starts a war, or rather, no one in his sense, ought to do so without first being clear in his mind what he intends to achieve by the war and how he intends to conduct it.

We see the protagonists, the antitreaty IRA side, try to win it militarily with no real political or strategic end state. They [believed] that just by killing more of the opposite sides, they would they would win the war.

As the war progressed, they weren’t offering an alternative [to the] the people, a strategic end state, a political matter. It just shows to me that you can’t win a war militarily. COA (course of action) counts for insurgency is only 20 percent military. It’s 80 percent everything else.

And, the Free State, or the pro-treaty side, realize that, and they competed for the popular will of the population by restoring essential services, the economy, governance, and providing an ulterior end state of a free state that’s not yet a republic, but it’s a stepping stone to a republic.

And eventually, they won the popular narrative with the population, alienating and isolating the antitreaty IRA side.    

Host   

A key pillar of the Irish Free State success was the use of locally recruited soldiers and police who lived among the population, which contrasts with modern approaches that rely largely on isolated forward operating bases. What are the key advantages of this embedded local-first approach, and why do you think it is so difficult for modern military forces to replicate?

Prendergast  

I agree with that 100 percent because when I was a young officer in Lebanon, back in the early 1990s, we lived in the towns and villages. We had our platoon bases inherent and embedded with the local population. We would have our meetings with the mayors and the mukhtars on a weekly, if not daily, basis.

Now, that was dangerous, but it still afforded us a common bond with the people we were there to protect, and you can’t just commute to work, as they say in counterinsurgency. But, as it got more dangerous, the Irish and other UN nations retreated into bigger bases, and I think the same happened in Iraq and Afghanistan, during the conflict. John can correct me if I’m wrong.

It was only during the surge that they later came back out and started to push into the population areas. And, I’m saying that the Free State, the national army during the Irish Civil War, realized this, and they realized that they had to spread out into the Irish countryside. And in total, they set up nearly 380 bases throughout Ireland with an army that rose to the size of 60,000 soldiers.

And, even in the county of Cork, where I concentrate my studies, they set up 64 different platoon-size bases, so as to provide the security, to get the general information, and to basically win the confidence of the population. And, the British Army could never achieve that in the previous war of independence against the IRA. They say the young British soldier in the bases had as much strategic awareness as a soldier in Nepal as he has of Cork.

So, I think the lessons from the Irish Civil War are very prevalent today [regarding] what happened in Iraq, what happened in Afghanistan, and what might happen in the future. So,

there’s a lot of learnings from that.

Nagl   

I think that’s exactly right. And, I think there’s a question of risk. In order to succeed in these kind of wars, you have to be willing to accept risk for your soldiers in order to keep the population safer, and it is only if your soldiers are taking that risk in support of the population that the population will trust you with the information you need to reduce the insurgents and win the war. So, there’s a trust basis that has to be formed between the population and the people conducting the counterinsurgency, and it took a long time to develop that. And, some hard lessons had to be relearned, in both Iraq and Afghanistan, from previous conflicts, including the one that Gareth and I write about.

Host   

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