Partially in response to these commando operations, air forces began to use fortified parking spaces for aircraft. In addition to making it more difficult for commandos to get at the aircraft, the shelters provided some protection from air attack. In the North African desert during World War II, the protection was often no more than a three sided wall of sand. These crude fortifications evolved into concrete shelters that were basically bomb proof hangers. The United States has, since World War II, tried to build these shelters in any foreign air base American warplanes might be operating from. For example, in Asia, the U.S. has access to 1,412 such shelters in 52 air bases (about 18 percent of the total in the region). Nearly half (641) of these shelters are in South Korea. This is largely because the North Koreans have trained thousands of commandos to try and attack American aircraft on the ground. The U.S. has paid all or some of the cost for many of these shelters, particularly in nations where the United States has basing rights. But other nations that face the threat of war also build these shelters. India has 229 and Pakistan has 176. Taiwan, which confronts a hostile China, has 203. Commandos have adapted their tactics to this, carrying explosives designed to penetrate these shelters so that the aircraft within can be attacked.
Since World War II, air forces have feared commando attacks on their air fields, resulting in destruction of their aircraft on the ground. Since 1942, there have been 645 such attacks, resulting in the destruction of over 2,000 aircraft, and damage to more than that. Over a quarter of these aircraft were destroyed in 1942, as the British Long Range Desert Group and the newly formed SAS showed how it could be done. The Vietnam war saw a large number of these attacks by North Vietnam sappers. If there were ever a war between NATO and the Warsaw Pact during the Cold War, the Russians had thousands of Spetsnaz commandos trained for this sort of attack.