After NATO planes killed 24 Pakistani troops this weekend, Pakistan says it will no longer conduct business as usual with the U.S. Already, the country has closed an Afghanistan supply route, kicked the CIA off an airbase, and said it would boycott an upcoming international conference on Afghanistan.

Vali Nasr is a professor of international politics at Tufts University. From 2009 until earlier this year, he was a senior advisor to Ambassador Richard Holbrooke, U.S. Special Representative for Afghanistan and Pakistan. Vali tells Worldview how America’s relationship with Pakistan is rapidly changing for the worse, and how that may affect U.S. interests throughout the region.