KEY POINTS:
As Western forces brace for the expected Taleban spring offensive, Afghanistan is emerging as a conflict zone where George W. Bush may see his grand strategic alliance with Pakistan end up a casualty.
Pakistani President Pervez Musharraf is taking flak for the human bombs going off inside Afghanistan, amid growing suspicion in Washington that he has no stomach left to conduct America's war on terror in his backyard.
The White House is covering up its concern with brinkmanship. Vice-President Dick Cheney's unscheduled visit to Islamabad in February to warn Musharraf to rein in Pakistan-based Taleban and al Qaeda militants or face an aid cut by a Democrat-controlled Congress was a last-ditch attempt to get US foreign policy in South Asia back on track.
But Musharraf appears to be past US pressure at the moment. He faces civil unrest at home over his removal of Pakistan's Chief Justice, Iftikar Chaudhry, which could snowball and result in a loosening of his grip on power if the Army is forced to negotiate with an emerging civilian authority.
US-Pakistan relations have been on a downward spiral since Musharraf struck a controversial peace deal with tribal leaders in North Waziristan which Washington saw as a sellout.
Musharraf argued that military intervention had alienated locals and brought heavy troop casualties. Fearing mutiny by ethnic Pashtuns within the Pakistani Army who baulked at killing fellow tribesmen under American pressure, the Pakistani Government signed the Miramshah Agreement with North Waziristan tribal leaders in September.
Under the deal, Islamabad withdrew troops, released captured militants, agreed to compensate tribesmen for losses sustained during the military operation, and allowed them to carry small arms.
In return, tribal leaders offered to prevent incursions by Taleban and al Qaeda militants across the border with Afghanistan, a clause the Pakistani Government had no means to enforce.
This deal appears to have failed and US officials claimed cross-border incursions had risen after the North Waziristan accord.
The Bush Administration was in a bind. Musharraf's co-operation was falling short of US goals in the region. But sending American troops into the tribal areas was not an option, as it would have resulted in what the Bush Administration describes as a "shock to the stability" of the Musharraf Government. The US bombing of a Bajaur village last year had sparked widespread protest.
Musharraf knows the US will not lean too heavily on him as long as there is no successor in sight to carry the burden of American interests in the region.
There is also the nightmare scenario of who will have his finger on Pakistan's nuclear arsenal.
The minute Cheney's back was turned after he came calling to deliver a tough message, the Pakistani Government inked an agreement with the tribal leaders of Bajaur, similar to the one signed in North Waziristan. Washington felt snubbed.
Clearly, Musharraf has reached a point where his domestic political agenda must override US strategic interests in an election year. But the free run enjoyed by insurgents in Pakistan's tribal areas not only contributes to instability in neighbouring Afghanistan.
The Bush Administration's counter-terrorism strategy is losing credibility, particularly after the plot to blow up transatlantic flights unearthed in the UK last July has been linked by Western intelligence agencies to training camps in Pakistan's tribal areas.
Bush is feeling the heat of Musharraf's soft line with the Taleban in Washington. The US Congress wants the White House to provide proof that Islamabad is cracking down on militants within its borders before it clears future military aid to Pakistan.
In other words, Bush will no longer enjoy carte blanche on what he can offer Pakistan, the fifth-largest recipient of American aid. Still, he continues to endorse Musharraf in public.
"The dilemma the Administration faces is 'What do you do without making the situation worse?"' says Robert Oakley, former US Ambassador to Pakistan.
Musharraf stays in the picture as long as there is no alternative voice coming out of Islamabad representing a new leadership that is ready to court unpopularity and toe the US line.
This would explain why the White House is not vocal in its demand for the restoration of true democracy in Pakistan.
US officials recognise that Musharraf's hold on power rests on military backing.
Musharraf has kept US interests alive despite a groundswell of anti-US sentiment building within the Pakistani Army, the intelligence services and on the streets.
The Pakistani President misses no opportunity to highlight his contribution to the war on terror, which is readily endorsed by US officials.
"Musharraf has done a lot for us, at a great danger to himself and his political position in Pakistan," David Smith, a former US attache in Islamabad, told the US-based Council on Foreign Relations.
Pakistan claims to have killed or captured key Taleban and al Qaeda leaders, including the March 2003 arrest of Khalid Sheikh Mohammed, the alleged mastermind of the 9/11 attacks, and the handing over of Abu Farraj al-Libbi, the Libyan described as the third most senior leader of al Qaeda, to US authorities last year.
Bush hailed the arrests as a "critical victory in the war on terror". Pakistan continued to get the aid and military hardware it needed from the US.
But the US-Pakistan ties were smooth only as long as Musharraf's vision for Pakistan aligned with Bush's vision for America. Afghanistan drove a wedge into that partnership when President Hamid Karzai complained to Bush that Musharraf was doing a bad job of policing the long porous border that separated them.
The problem is one of cultural overlap. Pakistan's 28 million ethnic Pashtuns share a common heritage with 12 million Afghan Pashtuns across the border.
Musharraf's problem is that though his Government has severed links with the Taleban since 2001, the Pashtun tribesmen identify strongly with them.
Congressman Gary Ackerman sums up the opinion in Washington: "What we truly need in Pakistan is someone else to talk to. The Administration seems content to only speak with President Musharraf and portrays him as the indispensable man.
"The truth is, for our goals to be achieved in Pakistan, there should be more than one phone number there to dial."
