The Arab World has maintained a long and problematic history with Western military bases on its territory. Until at least the 1940s, imperial powers often maintained that these bases were designed to defend regional nations against foreign invaders, but they also were used to pressure and sometimes control client governments. However necessary and important such pressure might have been during World War II, it was still a series of infringements on sovereignty that formed an important backdrop for Arab views on U.S. basing issues. Nationalist ferment against foreign bases was a key component of Arab politics throughout the 1950s and 1960s. In response to these regional political concerns, as well as changing Western military requirements and economic pressures, the U.S. and British military presence in the Middle East declined steadily, and a number of major Western bases were evacuated. By the early 1970s, the U.S. and British military presence in the area had been scaled down dramatically, and other issues had become more prominent in Arab-American relations. The 1990 Iraqi invasion of Kuwait introduced a major shock into the Arab system, and Saudi Arabia allowed large numbers of U.S. and other troops to be stationed on its soil as a prelude to the liberation of Kuwait in 1991. Significant numbers of U.S. forces remained in Saudi Arabia for another 12 years following Saddam's 1991 defeat by coalition forces, establishing a new military reality in the region. Additionally, Bahrain and Oman strengthened existing agreements with the United States in the aftermath of Operation DESERT STORM, while Kuwait, the United Arab Emirates, and Qatar negotiated new security agreements. Nevertheless, in the years following 1991, many of the old concerns about the political meaning of a Western military presence in the region re emerged. Saudi Arabia, in particular, began to repeat the earlier pattern whereby large and important Arab states often find it embarrassing to rely too publicly on the West for their military security. Additionally, these same states may have difficulty presenting themselves as important voices within the Arab World if they appear to be disproportionately influenced by the West and dependent on it for national security concerns. The United States and Saudi Arabia eventually reached an agreement for the withdrawal of almost all U.S. military forces in 2003, although the two countries remain close, and the United States continues to be a major arms supplier to the Saudis.