The U.S. Department of Defense tries to keep track of countries that have established Cyber War organizations, or just capabilities. Now Germany has joined the ranks of countries with a formal Cyber War organization. Germany is putting together a Cyber War unit. It is small, with less than a hundred personnel. But Germany has a large number of Internet technology experts, and many civilian resources for a Cyber War unit draw on.
Many of these Cyber War capable nations are trying to develop tools and techniques for attacking American military and civilian targets, via the Internet, in the future. In some respects, these Cyber Wars have already begun. In the last few years, the number of intrusion attempts on Department of Defense computers has grown to over 500 a day. The actual increase may be less than that, because as the Department of Defense increases its Internet defenses, it becomes better able to detect intrusion attacks. The number of intrusions that succeed, or at least the ones that were discovered, has been going down. But even a few successful intrusions can result in the loss of enormous amounts of valuable data.
A lot of information on the Cyber War against the United States is kept secret, since if the attackers know which of their operations are being observed, or even known about, they will take steps get their work back into the shadows. Half the battle in Cyber War is knowing you are being attacked. The best attacks, especially to steal information, or set up monitoring programs, work best, if at all, if they are undetected.
In the United States, the U.S. Air Force has taken the lead in developing Cyber War weapons. Air force hackers are usually the first to spot new enemy intrusion techniques, and are believed to have created powerful intrusion tools and techniques themselves. It's telling that intrusions of Department of Defense computers get publicized, while you hear little about such attacks made on other countries. It could be that the United States is not making as many intrusion attempts as are known Cyber War users like Russia and China, or that most of these intrusion attempts go undetected (whether they succeed or not.)
Another reason for the large number of detectable attempts on Department of Defense computers is that the United States is the highest profile target for such attacks. The detectable attacks are often by amateurs, although some of these have been tracked back to government computer systems in Russia and China.
The U.S. Air Force has many electronic warfare aircraft, and access to U.S. electronic warfare satellites. The plan is to use all these resources in any future Cyber War, finding enemy vulnerabilities wherever and whenever, and exploit them as quickly as possible. With so much of the world's electronic communications going wireless (including via satellites), this gives the air force lots of opportunities. But until there's an war, the public won't know how extensive the American Cyber War arsenal is, and how effective it can be.
An air force attempt to take overall control of American Cyber War efforts, by establishing a large (40,000 personnel) Air Force Cyberspace Command (AFCYBER), did not succeed. This effort sought to combine Internet operations organizations with some of the older electronic warfare ones. All this upset the other services, who had their own Cyber War activities, and this opposition, and resistance to overall air force management by the Department of Defense, led to AFCYBER's ambitions being sharply curtailed. AFCYBER is still out there, waiting for an opportunity to show the Department of Defense, and the rest of the world, what they are capable of.