The Special Forces definitely have a diplomatic function as well. When a Special Forces team shows up in a foreign country, and the locals realize that several of these rough looking characters speak their language and know some of the customs, this makes a positive impression. The Special Forces are specifically trained to make a good impression and establish long term relationships with some of the troops they train, advise or support. The media has never caught on to just how valuable this work is. In fact, most media coverage of Special Forces work overseas tends to interpret is as the Green Berets consorting with foreign death squads and uniformed murderers. The army and CIA would just as soon not have the media getting into what Special Forces does overseas. Its not that the troops are doing anything illegal, but they are collecting valuable information and contacts in volatile parts of the world. This kind of work is a lot harder if you have a bunch of journalists chasing after you.
Most Americans don't notice this, but around the world, especially in poor countries, the American armed forces are much admired, especially elite units like the Special Forces. The reasons for this are complex. Some of it has to do with the track records of the U.S. armed forces. That is, the American armed forces has been used mainly for defensive wars (except for Mexico, not many "wars of conquest.") During World War II, the U.S. emerged among the winners, and as a genuine military superpower. But there are two other reasons that are less remarked on. First, a lot of foreigners have received favorable reports about American troops from relatives in the United States. America is a nation of immigrants, and many of their kids joined (either voluntarily or because of the draft) and came back with a favorable opinion (compared to a lot of foreign forces, the U.S. comes out way ahead, especially in terms of treatment and living conditions for the troops.) And then there is the media angle. All those American movies featuring favorable (or at least scary) images of American troops leaves a vivid impression. Finally, Special Forces learned over the years to pay particularly close attention to local customs and not come on like superhuman know-it-alls. A little modesty and genuine eagerness to help goes a long way.
In the early 1960s, the Special Forces established the concept of 4-12 man MTTs (Mobile Military Training Teams.) In 1962, 1512 Special Forces troops operated in 19 different countries. This activity, which didn't always use Special Forces personnel, got buried, but never disappeared entirely, during the Vietnam war and the aftermath in the 1970s. But in the 1980s there was an MTT revival. In 1978, there were only 53 MTTs sent overseas, by 1982 this had grown to 260 (in 35 countries.) In terms of "man weeks" spent by MTT troops overseas, the number went from 1161 in 1980 to 5787 in 1984.
Since the 1980s, the Special Forces proved to be a reliable source of skilled, professional and seasoned soldiers for tasks that required all of those qualities. They have served successfully as long range scouts (during the 1991 Gulf war), as very effective combat troops (during the 1989 operations in Panama) and, in dozens of countries, convincing representatives of the United States and the U.S. military. They are much sought after as trainers. The CIA likes to work with the Special Forces (as they have for half a century) and even the State Department finds them useful. The Special Forces have also made themselves very useful in peacekeeping operations, where they made a favorable on many anti-American NGOs (Non Governmental Organizations providing aid for the locals.) All this work is unknown partly because the Special Forces like it that way. Special Forces are, after all, commandos and it's a matter of life in death for a commando to stay out of sight and always able to use the element of surprise. The Special Forces remain a unique commando organization. No other nation has anything like it. The Special Forces are a uniquely American organization, commandos who are as useful in peacetime as they are dangerous in battle.
Peace Commandos- One remarkable thing about the Special Forces is that they are commandos who have a clearly defined and very useful peacetime mission; training troops in nations friendly to the United States. Even before the Vietnam war, it was understood that the Special Forces were most useful in peacetime for training friendly (or even semi-friendly) armies. A Teams were originally set up so that they can train a battalion size force, and they still do that. For example, in the last few years, one battalion of the 3rd Special Forces Group has trained more than 5,500 African troops.