I was walking with great caution. We had all been warned these glowering Afghanistan tribesmen would fight, and none of them were likely to be pushovers. I also knew that one false step, a dislodged rock, however small, would betray our positions. Those tribesmen had lived up here for centuries, and they had eyes like falcons. If they heard us or saw us, they would attack immediately. Our high command had left no doubt in our minds. This was dangerous stuff, but we had to stop the influx of armed terrorists.

Carefully I moved along the ridge, occasionally stopping to scan the mountain pass with my binos. I was walking silently. Everything was clear in my mind. If a troop of wild tribesmen with camels and missiles came rolling into the pass, I must instantly whistle up reinforcements on the radio. If it was a lesser force, something we could deal with right here, we’d swoop and try to capture the leaders and take care of the rest by whatever means were necessary.

Anyway, I continued my silent patrol, hunkered down behind a couple of huge boulders, and again scanned the pass. Nothing. I stepped out once more, into steep, barren, open country, and below me I suddenly saw three armed Afghanistan tribesmen. My brain raced. There was seventy yards between me and Shane. Do I open fire? How many more of them were there?

Too late. They opened fire first, shooting uphill, and a volley of bullets from their AK-47s slammed into the rocks all around me. I hurled myself back behind the rocks, knowing Shane must have heard something. Then I stepped out and let ’em have it. I saw them retreat into cover. At least I’d pinned them down.

But they came at me again, and again I returned fire. But right then, they unleashed two rocket-propelled grenades (RPGs), and thank God I saw them coming. I dived for cover, but they blew out one of the boulders which had given me shelter. Now there were ricocheting bullets, dust, shrapnel, and flying rock particles everywhere.

It felt like I was fighting a one-man war, and Christ knows how I avoided being hit. But suddenly, the echoes of the blast died away, and I could hear sporadic gunfire from these three maniacs. I waited quietly until I believed they had broken cover, and then I stepped out and hit the trigger again. I don’t know what or who I hit, but it suddenly went very quiet again. As if nothing had happened. Welcome to Afghanistan, Marcus.

This was one type of patrol, standing guard up there over the passes and trying to remain concealed. The other kind was a straight surveillance and reconnaissance mission (SR), where we were tasked with observing and photographing a village, looking for our target. It was always expected we would locate him since our intel was excellent, often with good photographs. And we were always in search of some sonofabitch in a turban who had for too long been indulging in his favorite pastime of blowing up U.S. Marines.

On these sorties into the mountains, we were expected to pick out our quarry, either with high-powered binoculars or the photo lens of one of our cameras, and then swoop down into the village and take him. If he was alone, that was always the primary plan of the SEALs: grab the target, get him back to base, and make him talk, tell us where the Taliban were gathered, locate for us the huge ammunition piles they had hidden in the mountains.

That high explosive had only one use, to kill and maim U.S. troops, up there in support of the elected government. We found it well to remember those Taliban insurgents were the very same guys who sheltered and supported Osama bin Laden. We were also told, no ifs, ands, or buts, that particular mass murderer was right where we were going, somewhere.

Generally speaking, we were to grab our man in the village if he was protected by, say, only four bodyguards. No problem. But if there were more of them, some kind of Taliban garrison crawling with armed men, we were to call for a proper fighting force to fly in and take care of the problem. Either way, when we arrived, things ceased to look great for young Abdul the Bombmaker measuring out his dynamite down there in Main Street, Mud Hut Central, Northeast Afghanistan.

Our next mission was a huge operation, around fifty guys dropped into the mountains, in the worst terrain you’ve ever seen. Well, maybe not if there are any mountain goats or mountain lions among my readers, but it sure as hell was the worst I’d ever seen. There were steep cliff faces, loose footing, sheer drops, hardly any bushes or trees, nothing to grab, nowhere to take cover if necessary.

I have explained how supremely fit we were. We could all climb anything, go anywhere. But — you’re not going to believe this — we took eight hours to walk one and a half miles. Guys were falling down the goddamned mountain, getting hurt, bad. It was hotter than a Texas griddle, and one of my buddies told me later, “I’d have quit the teams just to get out of there.”

I know he didn’t mean it. But we all knew the feeling. We were tired, frustrated, roped together in teams, crawling across the face of this dangerous mountain with full rucksacks and rifles. To this day it remains the worst journey of my life. And we weren’t even facing the enemy. It was so bad we made up a song about it, which our resident expert banjo player put to the music of the Johnny Cash song “Ring of Fire”:

I fell into a hundred-foot ravine,

We went down, down, down, and busted up my spleen,

And it burned, burned, burned — that Ring of Fire . . .

Our dual targets on that next mission were two Afghan villages set into the mountainside, one above the other. We had no clues which one harbored the most Taliban forces, and it had been decided we needed to take them both at gunpoint. No bullshit. The reason for this was a very young guy. We had terrific intel on him, from both satellites and the FBI. We did not, however, have photographs.

I never knew where he was educated, but this young Taliban kid was a scientist, a master of explosives. We call them IED guys (improvised explosive devices), and in this part of the mountains, this kid was King IED. And he and his men had been wreaking havoc on U.S. troops, blowing stuff up all over the place. He’d recently blown up a couple of U.S. Marine convoys and killed a lot of guys.

Foxtrot Platoon regrouped in the small hours of the morning after the trek across the mountains and positioned ourselves high above the upper village. As the sun came up, we moved swiftly down the hillside and charged into the village, crashing down the doors to the houses, arresting anyone and everyone. We were not shooting, but we were very intimidating, no doubt about that. And no one resisted. But the kid wasn’t there.

Meanwhile the main force, SEAL Team 10, was in and playing hell in the bigger, lower village. It took them a while, because this required interrogation, a skill at which we were all very competent. In these circumstances, we were grilling everyone, looking for the liar, the guy who changed his story, the guy who was somehow different. We wanted the guy who was obviously not a goatherd, as the rest of them were; a young guy who lacked the gnarled, rough look of the native mountain farmer.

We got our man. It was my first close-up encounter with a fanatical Taliban fighter. I’ll never forget him. He was only just old enough to have a decent beard, but he had wild, crazy eyes, and he stared at me like I’d just rejected the entire teachings of the Koran.

I knew in that instant that if he could have killed me, he would have. No one had ever looked at me before, or has since, with that much hatred.

That second operation in Afghanistan, the snatch-and-grab of Abdul the Bombmaker or whatever the hell his name was, brought home two aspects of this conflict to us newly arrived SEALs. First, the rabid hatred these Muslim extremists had for all of us; second, the awkwardness of complying with our rules of engagement (ROE) in this type of warfare.