RAWALPINDI, Pakistan — In what could be the biggest change in a decade in a relationship that has been a mainstay of U.S. military and counterterrorism policy since the 9/11 terror attacks, the United States and Pakistan are lowering expectations for what the two nations will do together and planning for a period of more limited contact.

The change described by both Pakistani and U.S. officials follows a series of diplomatic crises over the past year that strained an already difficult partnership based around the U.S. goal of stability in Afghanistan and Pakistan and a reduction in Islamic-inspired terrorism.

For Pakistan, cooperation on that agenda was rewarded with billions in financial aid. The change means less cooperation with Washington and a willingness to swear off some aid that often made Pakistan feel too dependent, and too pushed around.

For the United States, scaling down an expensive military and economic program that has not met expectations could come at the cost of less Pakistani help in ending the war in next-door Afghanistan.

Both U.S. and Pakistani officials said the November killing of 24 Pakistani soldiers in a NATO airstrike and Washington's refusal to outright apologize for the deaths has been a game changer in a relationship characterized by mistrust and mutual acrimony.

Pakistan's loudly angry reaction has, if anything, hardened attitudes in Congress and elsewhere that Islamabad is untrustworthy or ungrateful.