As much as a test of intelligence gathering and military operations, US cooperation with Pakistan in the war on terror is fast becoming a showcase of acrobatic diplomacy, as both sides seek to cover up deepening cracks in the relationship.
While acknowledging Pakistan as a "key ally," a succession of high-powered US visitors visited Islamabad in recent weeks to urge the leadership under President Pervez Musharraf to "do more" to stamp out Taliban and Al-Qaeda elements near the Afghan border.
"On the surface we hear them saying they have a close relationship but in reality there is a lot of tension," said Talat Masood, a retired lieutenant general in the Pakistani army.
<b1>The urgency has grown with an improvement of the weather that is expected to bring a new Taliban offensive in Afghanistan with thousands of fighters and suicide bombers, many of who are thought to have infiltrated from Pakistan.
There is meanwhile mounting domestic pressure on the Bush administration to "get tough" with Pakistan.
US Senate Democrats now want to withhold delivery of F-16 fighter planes to Pakistan if it does not intensify its campaign against terrorism while the House of Representatives wants to condition all US military aid to stronger Pakistani efforts.
In Islamabad, the defence committee of the National Assembly lower house of parliament said Friday that if adopted, the legislation would be "uncalled for and amounts to downgrading our contribution".
Such a move "calls for a reciprocal action by Pakistan, including complete or partial non-cooperation in the war against terror," a statement said, calling for a full parliamentary sitting to discuss the issue.
The visiting US heavyweights officials included Defence Secretary Robert Gates followed by Vice President Dick Cheney in late February.
The latter's short, no-frills trip stirred speculation that he did indeed get tough with Musharraf, leaving officials in Washington bending backwards to avoid any mention of confrontation.
Asked if the Pakistani leader was keeping his commitments in the war against terrorism, White House spokesman Tony Snow said, "I think the appropriate question is, is he doing what he can? Is he committed to winning? And the answer is yes."
Musharraf this week denied that Islamabad and Washington were heading towards a showdown, referring instead to "fine tuning" of the relationship.
But the general-turned-president is no stranger to US tough talk.
Musharraf noted in his memoirs that he first signed up to the war on terror when after the 9/11 terror attacks on the US that then Secretary of State Colin Powell told him directly: "You are either with us or against us."
Today the talk is mainly of choking Pakistan's military aid if it doesn't come up with the goods. But Musharraf's opponents insist that he is betraying national interests through blind cooperation - a stance that analysts say will win public support if Pakistan is now penalised.
"What (the parliament of) Pakistan is doing now is reacting in advance. If the legislation is passed the people will become more anti-US and say it is a very unreliable friend," Masood said.
Pakistan's ambassador to the US, Ali Durrani, has warned that American pressure to "do more" could undermine Musharraf and destabilize the country.
Ahead of an expected visit to Islamabad this month by US Undersecretary of State Nicholas Burns to discuss strategic ties, the Pakistani foreign office is being careful to mirror the non-confrontational tone of the White House.
"In the past there have been ups and downs and there is this realization that whenever our relations have been less cooperative, both sides have paid a price for that," ministry spokeswoman Tasneem Aslam said.