 Complete the following phrase:  After the a href91120attacks911 attacksa, Putin supported the U.S. in the War on Terror, thus creating an opportunity for deepening the relationship with the leading Western and NATO power. On 13 December 2001, Bush gave Russia notice of the United States unilateral withdrawal from the Anti-Ballistic Missile Treaty. From Russias point of view, the US withdrawal from the agreement, which ensured strategic parity between the parties, destroyed hopes for a new partnership. Russia opposed the expansion of NATO which happened at the 