April 17, 2012: This month, Russia moved an S-400 anti-aircraft missile battalion to Kaliningrad. This is the former German city of Konisgberg, which was captured at the end of World War II and kept by Russia as the boundaries of Eastern Europe were rearranged in the late 1940s. Until 1991, Kaliningrad was on the Soviet Union's western border. But when the Soviet Union dissolved that year, and more than half the Soviet Union split away to regain their independence as 14 new nations, Kaliningrad found itself nestled between Poland and Lithuania. The small (200 square kilometers, 400,000 Russians, the Germans were expelled 60 years ago) city is still the headquarters of the Russian Baltic fleet and protected by a large force of troops and warplanes.

There are five S-400 battalions in service. Each S-400 battalion has eight launchers, each with two missiles, plus a control center and radar. Russia has already deployed S-400 battalions to Moscow and the Far East. Russia has 160 older S-300 battalions but a third of these are not in service (and are supposed to be in storage, just in case). The S-300 was known to NATO, during the Cold War, as the SA-10. This is a system that entered service in the late 1970s and was upgraded several times since then. The one upgrade came to be called the SA-12 and it entered service in the late 1980s. Finally, there was the SA-21, which was so different from the original S-300 that it was given a new name by the Russians: the S-400. These systems began entering service, slowly, in 2007.

The S-400 is similar to the U.S. Patriot and is expensive. Russia is now offering to export the S-400, despite all the advanced technology in it. The S-400 missiles weigh 1.8 tons each, are 8.4 meters (26 feet) long, and about 50cm (20 inches) in diameter. The missiles have a range of some 400 kilometers and can hit targets as high as 100,000 feet. The missile has a 145.5 kg (320 pound) warhead. The target acquisition radar has a range of 700 kilometers.

The S-400 has over five times the range of the U.S. Patriot, weighs twice as much, and claims the ability to detect stealthy aircraft. The S-400 also has an anti-missile capability, which is limited to shorter range (3,500 kilometers) ballistic missiles. That would mean a warhead coming in at about 5,000 meters a second (the longer the range of a ballistic missile, the higher its re-entry speed).

The S-400 system actually has two types of missiles, one of them being smaller with a shorter range (120 kilometers). These are deployed four to a launcher, like all other S-300 systems. The S-400 has no combat experience but U.S. intelligence believes that the tests these systems have undergone indicate it is a capable air defense weapon. Just how capable won't be known until it actually gets used in combat.