I stumbled off the dark, curtained bus into the blinding desert sunlight. A sergeant shouted for volunteers to unload gear. I lit a cigarette in the marginal shade afforded by a mesh tarp staked out in the sand and watched as soldiers from the 82nd Airborne tossed heavy canvas duffel bags into heaps from the backs of trucks. The temperature was already 45 C, and it wasn’t quite 9am.

A young Marine with an M-16 slung over his shoulder pulled a bottle of water from a nearby pallet and unscrewed the top. I recognized him from the bus. He’d sat in the front seat, one of two designated shooters who were authorized to return fire in the unlikely event our bus was attacked on the highway.

“Hey shooter,” I said. “Not much to shoot at in Kuwait.”

He swished the warm water around in his mouth, spat into the dust, and grinned. “Yeah, but I’m ready,” he said. He was nineteen years old, and this was his first tour. He was headed for Iraq. I was headed for Afghanistan, on assignment for Harper’s Magazine. I snapped a photo of him, M-16 in one hand, bottle of water in the other, his chin tilted up like a boxer about to enter the ring.

We dragged our gear to a fleet of buses that took us to Camp Ali Al Salem, an airbase not far from the border with Iraq. Ali Al Salem was a transition point for soldiers rotating into and out of the war zone. Unlike the bases in combat areas that belonged to particular military units, Ali Al Salem didn’t belong to anybody. It had the listless atmosphere of a rural bus station. I didn’t expect to be there more than a day or two, but I was stranded there for a week.

Huge concrete blast walls ringed the camp. Inside the walls were row upon row of tents laid out in a grid, with wide, sandy lanes between blocks. Soldiers wandered from their air-conditioned tents to the air-conditioned mess hall or the air-conditioned MWR (morale, welfare, and recreation) buildings where they played ping-pong or checked their email. The sound of Ali Al Salem was a chorus of clicks and whirs as hundreds of air conditioning units cycled on and off, undercut by the steady drone of diesel generators the size of minivans.

It was late July, and hot. The temperature rose above fifty degrees during the day. The steel doorknobs on the latrine and shower trailers were hot to the touch. I spent a lot of time in the latrine trailers, reading the graffiti I found there because I had nothing better to do. Much of it was arcane, full of military acronyms and slang that only soldiers could understand. But one main theme stood out: soldiers were being stretched to the limits of endurance.

A few months earlier, in April 2007, the U.S. Department of Defense had extended combat tours from twelve to fifteen months. In the graffiti, soldiers expressed their growing fatigue and anger—mostly with each other. When they weren’t scribbling Chuck Norris jokes or questioning the fighting ability of other units, they were slamming soldiers who dared give voice to their dissatisfaction.

I can still vividly recall the upper case ballpoint handwriting of one soldier who listed the number of men killed and wounded in his unit. He didn’t plead for sympathy or prayer; he simply wrote down the numbers. The response was harsh for its tone of glib detachment. “Should’ve worn their eye-pro (short for “eye protection,” or goggles) one soldier wrote. Another soldier suggested that the wounded and killed should’ve trained harder, as if any soldier in the war had been trained to survive an IED blast, or to avoid getting shot by someone who looked to them like every other Iraqi civilian.

I began photographing the graffiti because I realized that it would soon be erased by the cleaning crews who regularly swabbed the stalls. I made a point of visiting every latrine trailer on base, squeezing into more than 100 stalls and shooting in the dead of night to avoid suspicion. The air conditioning in some of the trailers had broken down and the oppressive heat and stench made me dizzy. The graffiti you see here is almost certainly gone now.

I got a C-17 flight from Kuwait to Bagram Air Field (BAF) in Kabul, Afghanistan, where I spent three days. BAF was similar to Ali Al Salem insofar as it was a point of transition, except it was much larger, and it was set amid a bustling city, separated from it by razor wire, dirt-filled Hesco barriers, and concrete blast walls. Some areas of the base had yet to be cleared of Soviet-era landmines. The thousands of soldiers stationed at BAF, including many international troops, lived in metal Conex trailer ghettos, or in low concrete buildings behind gates and armed guards.

Most soldiers, however, passed through BAF en route to remote bases in the Afghan countryside. At BAF they stayed near the terminal in tents for a night or two, and relieved themselves in rows of Port-a-Johns. The graffiti I found in those Port-a-Johns was specific to soldiers serving in Afghanistan. For instance, ISAF—International Security and Assistance Force, or NATO soldiers in Afghanistan—took quite a beating. But overall, it shared the same form and spirit of the graffiti I’d read in the latrine stalls at Ali Al Salem. All soldiers were suspicious that rival units were having an easier time of it, and they were ruthless in their criticism of each other.

I flew from BAF to my final destination, Forward Operating Base (fob) Salerno, located in Khost, Afghanistan, within artillery range of the Pakistan border. fob Salerno was nothing like Ali Al Salem or BAF. The place was immaculate, including the latrines, perhaps because the base belonged to a single unit, the 82nd Airborne’s 4th brigade combat team. It was their home for an entire year, and I suppose it was a point of pride to keep the place tidy (they paid crews of local Afghans to pick up trash and clean the latrines).

A few weeks later, I returned to BAF on my way out of Afghanistan. I stayed there for a few more days, walking the sprawling base from one end to the other, looking for Port-A-Johns I’d missed the first time around. The day before I left BAF, on a hot August afternoon that brought a dusty wind whistling down from the mountains, turning the air a murky beige color, my camera suddenly stopped working, and my survey of latrine graffiti came to an end.

It’s tempting to view these photographs as the “true” or “authentic” voice of American soldiers. But that would be missing the point. Graffiti is public by definition—it’s not a private confession. It’s a surface effect of something far broader and infinitely more complicated than what can be contained in a hastily scribbled line or two.

I look at these photographs and read the words in the same way I read the expression on the face of that 19-year old Marine I met on my first day in Kuwait. When I snapped his picture, he took a moment to pose. He wanted anyone who might later look at the photograph to know that he was tough, that he wasn’t frightened, that he was ready for whatever was coming his way in Iraq. But his expression at that moment wasn’t the sum of who he was, just as the graffiti you’re reading here isn’t the whole truth about what American soldiers think and feel about the wars in Iraq and Afghanistan.

So how should you look at the graffiti in these photographs? As a fleeting moment in a six year-old war—nothing more. The words on these walls are snatches of an overheard and ongoing conversation that changes by the day, soldier’s talking to other soldiers at a time when soldiers are being asked to give more than they have been giving, which is already too much.