It looks like the proverbial marriage of convenience; although international obligations and strategic considerations continue to serve as the glue for an increasingly volatile partnership between the United States and Pakistan, deep-seated mutual mistrust and conflicting geo-strategic objectives prevent Pakistan and the United States from partnering in a friction-free way. This is how one could characterize the bilateral relationship following Chairman of the Joint Chiefs of Staff Adm. Mike Mullen's terse meetings last week with the Pakistan Army high command during his trip to Pakistan, and the unusually blunt remarks by Mullen to several Pakistani media outlets just before the meeting left little doubt that both sides remain divided on some of the most fundamental issues related to Pakistan's fight against militants.

The interviews Adm. Mullen gave before his talks with his counterpart General Khalid Shameem Wynne, as well as with General Ashfaq Kayani, the Pakistani army chief,  reflected the American frustration with the Pakistani reluctance in dealing with groups such as the Haqqani Network and Lashkar-e-Taiba (LeT) the way Washington (and New Delhi) would want.

"It is fairly well known that ISI had a relationship with the Haqqani network and addressing the Haqqani network from my per spective is critical to the solution set in Afghanistan. ... that's at the core -- it's not the only thing -- but that's at the core that I think is the most difficult part of the relationship," Admiral Mullen said in an interview with Dawn TV late Wednesday.

This essentially reflected what Mullen said in January this year, when he called Pakistan the "epicenter" of terrorism in the world, and called on the Pakistani safe havens where the Haqqanis, LeT, al-Qaeda and the Pakistani and Afghan Taliban reside. Speaking to reporters the day before his trip to Pakistan, Mullen also said that, "We're working our way through the relationships that [Pakistani intelligence] has with the Haqqani network and the strain that that creates... and these are issues I address with him (Gen.Kayani) every single time we engage."

And if the brief press release put out by the U.S. embassy or the stern response from the General Headquarters in Rawalpindi south of Islamabad were any indicator, Mullen's  "engagement with Kayani" was not a smooth affair at all.

"U.S. Navy Admiral Mike Mullen, Chairman of the Joint Chiefs of Staff, was in Pakistan today to consult with Gen. Ashfaq Parvez Kayani, Pakistan's Chief of Army Staff," was how Kayani figured at all in the 124- word statement issued after Mullen's 22nd visit to Pakistan since October 2007. As for Kayani, he ""strongly rejected negative propaganda of Pakistan not doing enough and Pakistan army's lack of clarity on the way forward" according to the statement released by the Pakistani Army.

Let us now consider why Mullen's patience has worn thin with Pakistan, after long being known as a defender of the Pakistani military; only a few months away from the scheduled beginning of the phased withdrawal of U.S. troops from Afghanistan, the U.S.-Pakistan relationship has been racked by the controversy surrounding CIA operative Raymond Davis after he killed two armed men in Lahore in January. This episode not only exposed the CIA operations in Pakistan that for the most part until Davis's release had been suspected but not paraded about in broad daylight. It also certainly delivered a serious jolt to the relationship, and provided Pakistan with a wand to wave at the United States in order to extract some concessions on covert CIA activities in Pakistan.

And this has turned it into an ISI-CIA turf-war over their mutually conflicting interests and objectives in the region - namely that the Americans want Pakistan to conclusively move against the Haqqani Network and LeT, while Pakistan wants to secure its future interest in a post-American Afghanistan, while also wanting to maintain some order in North Waziristan, dominated by the Zadran tribe, who are also spread across Afghanistan's Paktia province and to which the Haqqanis belong.

It would seem that Mullen failed to extract a commitment from Kayani on this front, while Mullen, on the other hand, seems to have failed in committing himself to addressing the Pakistani establishment's paranoia with the expanding Indian role in Afghanistan, a concern that a senior Pakistani general told me the military has raised on various occasions with their American partners. This failure to openly address Pakistani concerns also reinforces the Pakistani preoccupation with the perceived U.S. tilt towards India.

The generals at army headquarters in Rwalpindi also believe that the Indo-American partnership, with the active support and connivance of a Tajik-dominated Afghan security establishment, wants to deny Pakistan a dominant role in Afghanistan, and believe the United States thinks that the only way to achieve this is to accord India key security responsibilities in that country once the bulk of foreign troops leave. Unless addressed by an increasingly strident American defense establishment upset by the deteriorating security situation in Afghanistan, these Pakistani concerns will likely continue to disrupt the bilateral U.S.-Pakistan ties, as well as the keep the regional multi-lateral relations on the boil. The perceived American deference to India works to the detriment of Pakistani interests, the senior general told me, and would hardly provide them with the comfort level that a "strategic partner needs to get fully involved in a war that has cost [Pakistan] a lot."

Pakistani intelligence, says the military commander, "cannot afford to relent and allow the United States or its security institutions a free hand in shaping the geo-political agenda in the region in league with the Indian and Afghan security establishments."

The challenge for both the U.S. and Pakistan remains the problem of trying to marry their divergent geo-strategic objectives. As for now, the relationship has soured significantly, with no indication of Pakistan giving in on the issue of support for the Haqqanis or LeT. Nor does the U.S. appear ready to accommodate Pakistani concerns flowing from the surging Indian influence in Afghanistan. And in such an environment, stalemate and tension seem ready to endure.

Imtiaz Gul heads the independent Centre for Research and Security Studies -- CRSS-Islamabad -- and is the author of The Most Dangerous Place.