At least this is what president Karzai said in an interview Afghanistan. Karzai said:"God forbid, If ever there is a war between Pakistan and America, Afghanistan will side with Pakistan," "If Pakistan is attacked and if the people of Pakistan needs Afghanistan's help, Afghanistan will be there with you." The statement is rather surprising since Afghanistan is quite dependent on U.S. aid and has had rocky relations with Pakistan of late.
No doubt the statement is in response to the harsh and aggressive warnings made by the U.S. against Pakistan. The U.S. has accused Pakistan of providing haven for the Haggani network militants and not doing enough to fight against them.
During her recent visit to Pakistan Hilary Clinton warned the country it would pay a "big price"if it did not meet U.S. demands. There was no mention of Pakistani demands that drone attacks end!
The Pakistan parliament passed a motion demanding that the drone attacks stop. The U.S. response has been to ignore the demand and even to escalate attacks. The fact that Karzai felt that he could safely say that he would side with Pakistan if the U.S. attacked shows the extent of anti-Americanism in both Afghanistan and Pakistan. If the U.S. actually sends in ground troops Karzai might react quite differently I expect. For more see this article.