Professionalism: Currently, the American armed forces are the largest professional military on the planet. Other nations have professional soldiers, but not as many as the United States. For thousands of years, it was recognized that professional soldiers were superior to part timers. But throughout most of history, few nations could afford an army of professionals, at least not on a permanent basis. It wasn't until the late 20th century that countries began to establish large, permanent, all-volunteer armed forces that were carefully recruited and trained for combat. Britain was the first, when it phased out conscription in 1962. In 1975, the United States followed suit. For over a century, conscription has been seen as the way to remain militarily strong without breaking the bank. But the conscripts did not stay in uniform long enough to get really good at fighting. Britain and American were the first two nations to realize that conscription was so unpopular that the voters would pay extra to maintain a professional force. Within a decade, an army of professionals begins to pay off. The professionals are not only more lethal on the battlefield, but are also, if carefully selected (for education and aptitude) more likely to constantly develop better ways to fight. This produces a tremendous battlefield advantage. It doesn't make you invincible, but it does make you very difficult to defeat.
Netcentric Operations and the Internet: Radio made the World War II Blitzkrieg ("lightning war" using fast moving tanks) possible. During World War II, soldiers got to know about the "radio net" and how important it was in combat. The radio net evolved slowly after World War II, until the Internet, and its spin off, the World Wide Web, appeared as a form of mass communications a decade ago. The professionals in the American military quickly saw the possibilities. By 2003, combat commanders were rolling through Iraq with one eye on a computer screen that showed where all the good guys were, and allowed instant messaging between everyone. This took the blitzkrieg up another level. The navy and air force have their own versions of the battlefield Internet. Although this is still a work in progress, netcentric warfare has become the key tool for fighting, and winning, faster and with fewer casualties on both sides.
Smart Sensors: Electronic devices that can detect enemy activity at great distances (radar, sonar, thermal imaging) have been around for nearly a century. But over the last two decades, these devices have been miniaturized and equipped with computers to create guidance systems for bombs, missiles and shells that pick out specific targets to attack. And do it all cheaply and reliably without any human intervention. As a result, weapons have become much more lethal, and warfare using robots is closer than you think.
Awesome Automation: Over the last few decades, commercial ships have become so automated that, no matter what their size, they can be reliably run with a crew of three dozen or fewer people. Automatic landing for commercial aircraft has been around for over a decade. Out of all this automation has come an explosion of UAVs (unmanned aerial vehicles) and warships with crews of under a hundred sailors. There are also unmanned land, surface and underwater vehicles. Wars are being fought with fewer people going into harms way. This has made commanders bolder, as they don't have to explain to a robots parents why their "child" is dead.
Training Like You Fight: Better sensors and computer technology have produced training devices (laser tag, photo-realistic wargames, Etc.) that, more than ever before, allow to troops to train very much as they will actually fight. This has not been possible before, and when troops go through this more accurate training, they are much more lethal on the battlefield.
The Speed of Change: New technology has been invented, and brought to market as useful products, at an ever increasing rate during the last century. The speed has picked up noticeably in the past two decades. The smart troops notice this, and take advantage of it. The American military has long been noted for the speed with which they adapt new technology for military purposes.
COTS: This stands for Commercial Off The Shelf. In other words, buying civilian gear that suits military purposes. The armed forces tradition has long been to build special "military versions" of everything from underwear to trucks. But there's an increasing quantity of civilian equipment that can be used as is. And in the American military, that's what's been happening at an increasing rate for decades. Note that this process has been energized by the Internet (troops share new ideas and discoveries via the web.) Typical new civilian technologies that have gone to war include cell phones (which have been used in combat), rifle accessories and cleaning materials, PDAs, all manner of PC related gear and much clothing developed for athletes and outdoorsmen.
The Department of Defense, military pundits, and even the media, have been going on about "transformation" and the "revolution in military affairs." It's true that warfare has been going through some heavy changes during the past decade or so, and even more change is looming in the near future. But the "revolution" is less a deliberate plan by the Pentagon than it is the troops simply taking advantage of new technologies and ideas. The American military has always been quicker than anyone else to jump on new military technologies. Think about it; the machine-gun, the submarine, the atomic bomb, the strategic bomber, and many other military technologies were invented by Americans. But the current revolution is less about the deliberate development of new weapons than it is quickly taking advantage of new technologies developed for non-military purposes. With that in mind, consider The Seven Pillars of Transformation;