For a nation at peace, the United States packs a hefty military punch.  Apart from a ten-division Army, 286-ship Navy and a 5,000-plane Air Force, they also can deploy 190,000 in the US Marine Corps—a force larger than all Britain’s armed forces put together. Unlike the Special Forces role of Britain’s Royal Marines, the USMC  is actually more like British paras, tasked to deploy in large units overseas, with their own aircraft and support units. Known as ‘jarheads’, marines are known for their young, aggressive attitude, which cause some unrest and high profile around the 20 marine bases scattered down America’s coasts. A recent crash of a marine F-18 fighter refeuling off the coast of Japan was a reminder that there are also another 20 marine bases scattered around the world.

But if jarheads don’t fill the role of commandos, who does? The less well known and probably most effective of the many weapons in the US arsenal are the Navy SEALs. Their name derives from their ability to deploy and be effective by SEa, Air and Land. Formed in 1962, their first deployment was to Vietnam where they quickly earned their spurs. While the bulk of the 500,000 U.S/ troops deployed (including Marines and Air cavalry)fought a conventional was against the elusive Viet Cong, SEALs were deployed to beat them at their own game.

Trained not just as elite infantry but they deployed specialist skills, including parachutist, frogmam, stealth, unarmed combat, survival off the land and fluency with various weapons and explosives. They were, as the Americans say, some mean dudes, especially those assigned to Long Range Patrols, known as ‘Lurps’. Navy SEALs are called on to perform missions of ‘strategic importance’. including: Direct Action: Neutralize, Capture and Kill Enemy Forces Offensive strikes against an enemy target using tactics like raids, ambushes and assaults. Special Reconnaissance: Observe and Report. Heaven help the village commissar they were tasked to eliminate. Deployed in small squads of four, they  penetrated all over South Vietnam, far into Cambodia and Laos and even deep into North Vietnam as far as Hanoi.

While such tasks could be undertaken by other branches of service but the trickiest tasks—and certainly those to be carried out deep hostile territory—would be entrusted to SEALs. That requires a rare breed: men at the peak of fitness with unswerving dedication, guided by astute intelligence, able to read and react swiftly and decisively in a myriad of unforeseen circumstances. All of this needed to be carried out professionally under the pressure of imminent death and a fierce loyalty to the handful of comrades taking the same spine-chilling risks with you.

SEALs proved so effective they have been used in every serious conflict the US has been involved in, from Somalia to Iraq, through Afghanistan to Syria and now in the Sahel. Eight ‘teams’ of several hundred each, ready for deployment and split between home bases at Coronado CA and Little Creek VA, But the toughest assignments must have been the myriad missions executed in the early days in Vietnam. Not only was this against a wily, tough and experienced enemy, but had to develop many of the skills now commonplace. These included exiting from a submarine at periscope depth and HALO (high altitude, low opening) parachute jumps to achieve safe and stealthy insertions.

Such an adrenalin-pumping life took its toll, The enemy was almost the least of the worries—very few SEALs died on engagement. But years in Vietnam of the tension of engagement and exposure to chemicals such as the Agent Orange defoliant in the field left returning SEALs with even more difficulty with re-entry in and acceptance by American society than the ‘grunts who served their 364-day ‘tour’. Even now, SEAL veterans are tight-lipped, stay close to buddies who walked through the same hell, show huge mistrust in ‘the system’ that put then in harm’s way and sometimes left them there unsupported to preserve ‘plausible deniability that America was ever involved. This extends to politics and government, for whom they have a bitter distrust.

And can you blame them? Their country created some of the most flexible, autonomous and effective fighting units, honing them to be fiercely self-reliant and trust no-one. Like a peak athlete or intrepid explorer, how do you return to the soft, easy civilian world and be content with it?