US suspects Pakistan's hand in Kabul embassy attack

US officials say there is growing evidence that Pakistan's intelligence agency encouraged a Pakistan-based militant group, the Haqqani network, to carry out last week's attack on the US Embassy and NATO headquarters in Kabul, Afghanistan.

The US and Pakistan have long been at odds over the links between Pakistan's intelligence agency and military, and Pakistani militant groups such as the Haqqani network. With the US preparing for a drawdown in Afghanistan, the presence of militant groups is now a top concern, as is Pakistan's quiet support for them.

The US has tried to pressure Pakistan into breaking its ties to militants, but has so far been unsuccessful – Pakistan sees the militant groups as necessary leverage in the region.

For several weeks after the American raid in May that killed Osama bin Laden on Pakistani soil, the relationship between the two countries seemed on the verge of severing, but relations improved over the summer. However, last week's attack in Kabul sent them spiraling downward once again amid US criticism of Pakistan for failing to crack down on the Haqqani network, Reuters reports.

"We covered ... the need for the Haqqani Network to disengage, specifically the need for the ISI [Pakistan's intelligence agency] to disconnect from Haqqani and from this proxy war that they're fighting," [Chairman of the Joint Chiefs of Staff Adm. Mike Mullen] said in a speech to the Carnegie Endowment for International Peace on Tuesday.

"The ISI has been doing this – working for – supporting proxies for an extended period of time. It is a strategy in the country and I think that strategic approach has to shift in the future."

"The increasingly tough U.S. rhetoric – particularly the accusation of a proxy relationship – reflects a US belief that Pakistani intelligence in recent months has more aggressively facilitated attacks by the Haqqanis on Afghan and American targets inside Afghanistan," a US military official told the Associated Press.

Pakistan's thinly veiled support for militant groups is particularly concerning, with the US drawdown in Afghanistan and peace negotiations between the Taliban and Afghan government on the horizon.