One of the less well known achievements of the U.S. Army Special Forces is the enormous impact it has had on how the army trains its combat troops. Special Forces training evolved from the highly realistic exercises developed by commando units during World War II. Live ammunition was used a lot, despite the risk of accidental injuries. This was considered a reasonable risk, because the Special Forces trainees were the same kind of high quality personnel who successfully did this sort of thing during World War II. Moreover, the Special Forces always had a number of actual combat veterans around to keep it real. But by the late 1980s, the number of combat veterans (from Vietnam) began to thin out. Despite that, in 1991. when Special Forces were used extensively in the war with Iraq, it was found that well trained Special Forces troops, with no combat experience, did very well in their first combat actions. 

In the 1980s, the rest of the army, now, like the Special Forces, composed entirely of volunteers, decided to try the more realistic type of Special Forces training. But not with real ammunition, but with lasers (the MILES system). The culmination of this new training was held at the National Training Center (NTC), which was rigged to electronically record everything that happened. This was a bit of a gamble, for the regular army combat troops did not possess the same high degree of natural talents as the Special Forces people. But the 1991 war showed that all the army troops that went through the new training performed as well as combat experienced veterans had in earlier wars. This was a rather surprising development. For thousands of years, despite strenuous training, it was believed that only exposure to actual combat created the most effective troops. Now there was a way to do it without "blooding" (and losing quite a few of) the troops in  combat. This was rather obvious during the 1991 Gulf War, where an American army composed largely of men who had never been in combat, easily crushed a force largely composed of combat veterans from the 1980s Iran-Iraq war (which had ended four years earlier.) The new training technology is also being applied to combat support troops, police and paramilitary personnel. 

While journalists have generally missed this momentous development, armed forces leaders around the world have not. The problem with gaining this training advantage is not so much the technology, but money. It costs thousands of dollars per year per soldier to undertake the specialized training. Moreover, your troops must be well educated (at least high school, and above average graduates at that), for it to work. You can make up for the lack of formal education by providing additional training at army expense. But this, obviously, drives up the cost. The extra expense is a major barrier for most nations, especially those (like China and India) who depend on larger numbers of troops to make up for a lack of technology. 

So, for the moment, this battlefield advantage remains the monopoly of a few wealthy nations. That will eventually change, as the training methods are improved, and the cost of implementing them comes down. Thats the future. For the moment, check carefully how your opponents were trained, before you pick a fight.