Sometimes in life, one experiences a shock or a revelation so powerful that it stays with you for years. For me, one such shock occurred at the Yavoriv training area in Western Ukraine, in June of 2015, embedded with the 173^rd Airborne Brigade, which was training about 2,000 members of Ukraine’s National Guard. The shock was seeing Ukrainian troops (many of whom had been rotated back to training from the front lines) performing at a level of competence equal to or even exceeding what I’d seen in U.S. forces during my time as an airborne infantry officer (from 2006-08, with the 173^rd).

The Ukrainians were unafraid of speed. Going door to door clearing a village of “separatists” they demonstrated a violence of action I hadn’t seen in years. These weren’t tier 1 units, they weren’t Delta or Rangers, they were regular units, albeit those who’d already seen some combat. Their practice runs were filled with the type of urgency and energy every commander hopes for in troops on the offense. For the first time, an assumption I had about Ukraine and Russia — essentially, that Russia would inevitably win — was challenged. Moreover, an assumption I’d had about American military formations was challenged. When I tested that assumption of mine, that the U.S. military was there to train the badly equipped, demoralized, hapless Ukrainians, many paratroopers with the 173^rd confirmed my suspicion, stating that they’d learned as much from the Ukrainians as they’d taught them. Some paratroopers went further, saying that the only thing Americans were really good for was as a delivery mechanism for bullets, that this was all the Ukrainians needed.

That was a bit much; Ukrainians I spoke with were deeply grateful for the training provided by the 173^rd. More than the bullets, they were also grateful for the process that American paratroopers used to approach training — backward planning, the deliberate design of a program from the end result (outcome) to the beginning inputs. That process, that ability to project out desired results and carefully and methodologically build up to them in a way that took the trainees capabilities and desired end state into account, was not something that was part of most Ukrainians’ experience. The extent to which serious and deliberate training had ever been part of the Red Army once upon a time had withered over years of corruption and disuse. The 173^rd, for its part, put the lessons it learned from Ukrainians to excellent use, compiling a remarkable document covered by author and journalist Wesley Morgan in 2017.

There in Yavoriv, watching the Ukrainians train, and the 173^rd Airborne Brigade train them, I thought about how suitable it was for my former unit to be offering the training. It occurred to me there that an effective military reflects the culture and society of the country it serves, and also that a culture and society supports a military that reflects its values. There is a kind of virtuous harmony between the two. I also thought then, remembering my own service with the 173^rd, how perfectly appropriate the airborne infantry (which prizes decentralized authority for decision-making and mission accomplishment) is for a people who prize democratic values and value as much political and economic authority as possible pushed down to the individual citizen level. Historically, those armies have always punched far above their weight.

Rob Williams, a former paratrooper with the 173^rd — who, incidentally, deployed to Afghanistan at the same time that I did (2007-2008) though with the Brigade’s 2^nd Battalion (I was in its 1^st Battalion) — has written an excellent book describing why and how that came to pass. The Airborne Mafia, out this March through Cornell University Press, covers the evolution of airborne operations from WWII to the present moment. It also examines how a small group of airborne leaders who emerged from WWII had an outsize effect on the shape and culture of the U.S. Army (and indirectly, on the military) after WWII.

The history isn’t simple, but the connective tissue is clear. Astonished by what it saw the Nazi military accomplish in WWII with airborne power, from the Wehrmacht’s key (and tactically unimpeachable) deployment during the initial blitzkrieg of Belgium and the low countries to German paratroopers’ Phyrric seizure of Crete, U.S. war planners became obsessed with fielding their own airborne capabilities. Williams catalogues the development of those forces in training and in war, highlighting key lessons in combat from Salerno to Normandy and beyond. These experiences formed the “seed” of the Airborne mafia.

Over the coming decades, that seed, carried by those leaders who had practiced airborne warfare in WWII (names with whom military aficionados and airborne infantrymen are familiar, including Gavin, Taylor, and Ridgeway) guided and advocated for the evolution of that force within the Army even as they defended it from hostile and competing influences, including (I was surprised to learn) a recalcitrant Air Force that wanted full control over all air assets but was actively hostile to serving as a ferry for Army combat power it believed technology had rendered obsolete.

Through Korea, Vietnam, and the Cold War, the key principles of the airborne infantry (radical decentralization of mission control down to the individual soldier level) were emphasized and spread, until the active-duty military became, on a certain fundamental philosophical level, indistinguishable from an airborne unit. This was the case when I was in the military on active duty, and as far as I can tell — again, on a fundamental level — is the case today.

Moreover, though he doesn’t put too much weight on this assertion (his focus is the airborne), Mr. Williams also makes a credible case for the importance of the airborne and the Airborne Mafia to the birth and growth of special operations. Both formally in terms of capabilities, and also culturally in the infusion of airborne noncommissioned officers into Rangers and Special Forces during Vietnam (the sort of career path described in Apocalypse Now), which in turn led to the development of CAG and other elite formations that form the heart of what people think of as America’s warrior elite, the airborne was a vehicle that carried special operations forward into the modern era.

The Airborne Mafia is a necessary work. Not only because it’s always necessary to lay out important information that’s visible with complete clarity in retrospect, but because in describing how the Army came to embody the ideals of the airborne infantry, Williams also offers a compelling defense for the airborne going forward in the 21^st century. No force save the Marines has come in for as much criticism as the airborne; no force save the Marines has been faced with extinction as many times. The critics of Marines and the airborne are legion: too expensive, strategically unnecessary, tactically wasteful, worse than useless. But those same critics rarely (if ever) consider the upside. That upside: that decentralized 21^st century warfare is most effectively trained by the airborne, in the airborne, and is most effectively prosecuted by leaders who have been raised and trained in that “paratrooper” mentality. Paratroopers embody combined arms warfare as much as they depend on it for survival; they are at the heart of a modern and effective combined arms force just as much as their leaders helped build that force. Without them, that force will crumble; without that combined arms military, the future of the United States becomes uncertain.

I will take it a step further. While Mr. Williams does not say it in the book, I believe the Airborne still has a role in the conventional Army for the 21^st century as the airborne — that 20,000 or 30,000 paratroopers, descending from the sky by parachute, can ruin an enemy’s defensive plans or blunt or parry an enemy’s dangerous offensive operation. Recent hyper fixation in certain quarters on special operations “Sicario” style strike teams and the usual chorus of voices claiming that technology (drones, missiles, etc.) have changed warfare forever notwithstanding, I believe — I know — that so long as the U.S. fields a healthy and capable airborne arm, that the military is in good shape, and reflective of the democratic values and principles our country still — for the moment — holds dear. When we cannot take to the sky to descend at a time and place of our choosing, it will be one more sign that the days of the United States are numbered.