A new system based in southern Europe and designed to intercept shorter-range missiles from Iran will likely replace the planned system, which was to comprise a radar system based in the Czech Republic and ground receptors in Poland.
In a speech at the White House on Thursday morning, Presdient Obama announced that the new plan will offer a "more comprehensive" system that will "enhance protection of all our NATO allies."
Listen to Defense Secretary Robert Gates answer questions about the decision:
The Bush-era missile shield system has long been controversial, particularly in Russia, where the Kremlin considered the system a threat to its security and an indication that the United States sought permanent military installations close to its border.
The initial system was designed to counter the threat of Iranian long-range, intercontinental ballistic missiles. But a spokesman for the Pentagon told reporters that recent "intelligence shows they [Iran] are much more fixated on developing capable short and medium range missiles," and that the new system would be designed to more effectively counter the Iranian threat by putting interceptors closer to Iran.
The decision to scrap the planned shield could anger governments in Poland and the Czech Republic, both staunch U.S. allies. Both governments publicly supported the shield and permanent U.S. military personnel based in their countries on the grounds that they would provide protection against Russia.
The new plan will likely be welcomed in Moscow as evidence that the Obama administration is following through on its pledge to "reset" U.S.-Russian relations. Russian Foreign Ministry spokesman Andre Nesterenko told reporters this morning that Russian officials "need to see the full text [of the plan] before we can make any comments. So far, I can say that a possible review of the U.S. position on missile defense would be a positive signal." He denied that any back-room deal had been struck between Moscow and Washington.
Thawing relations with Moscow could prove to a major boon to U.S. and Russian efforts to negotiate a replacement for the Strategic Arms Reduction Treaty, or START, which expires in early December.
An updated treaty, which is expected to cut the number of nuclear warheads and delivery systems on each side, is considered a key step in encouraging other countries to strengthen the world's nuclear non-proliferation system, one of Obama's stated goals.
---- Compiled from wire reports and other media sources