There’s never a good time to be worried about your health. But when Pakistani President Asif Ali Zardari flew to Dubai on Tuesday to undergo tests after what his spokesman called a “minor heart attack,” the rumors grew thick and fast that President Zardari would be ousted in a coup.

Pakistan is a rumor-prone place, despite having a fairly independent press, and both Pakistani and US officials were quick to tamp down any rumors of a military coup. But Zardari’s health problems come at a time when he is deeply unpopular with his own people, both over the usual issues of corruption and over his handling of international relations with the US, which have reached a nadir.

In theory, the US and Pakistan are allies in the fight against the same terrorist group, Al Qaeda, and supporters of a democratic regime in Afghanistan. But a spate of recent events shows how much the US-Pakistani relationship has soured.

The US capture and killing of Osama bin Laden on May 1, 2011, just yards away from a Pakistani military installation this year

The arrest and release of a CIA contract Raymond Davis for killing two Pakistanis on a motorbike in late January 2011

The continued US use of military drones over Pakistan, aimed at insurgents, but occasionally killing civilians as well

The apparently mistaken November 2011 bombardment of Pakistani soldiers by NATO forces in Afghanistan

And more recently, the withdrawal of Zardari’s ambassador to the US, Husain Haqqani, after news emerged that he supported the civilian government

As the man in the position to stand up to the Americans, Zardari is blamed by many Pakistanis, including some within the Pakistani military, for failing at his job. Opinion polls show that many Pakistanis would like to break off their alliance with the US and cooperation in the war against terror groups. So, while Zardari officials discount coup rumors, the conditions are certainly favorable for one.

"President Zardari's condition is stable, he is fine, he is OK," presidential spokesman Farhatullah Babar told AFP on Thursday. As for rumors of a possible coup, Mr. Babar called them "speculative, imaginary, and untrue."

Zardari appears to have taken senior members of his military staff along with him to Dubai, a move that could very well have been a measure to ensure that he was kept informed of news events back home, or that could also have been intended to ensure that Zardari would indeed be allowed to return back to the country after his treatment.

Yet one thing to keep in mind about coups d’etat in Pakistan – and indeed in any country – is that if the military is planning a coup, they generally don’t give warning. When President Nawaz Sharif attempted to replace Army chief Gen. Pervez Musharraf in October 1999, and to prevent his commercial flight from landing in Karachi, there were certainly tensions between the civilian and military, but nothing in the press suggested that a coup was imminent. Pakistan’s military responded by putting Sharif under arrest, taking over airports and major installations, allowing General Musharraf’s plane to land. They held power for the next eight years.

At the time, Musharraf’s aides seemed to be as surprised by the coup as the world was. Consider this comment by Brigadier Rashid Qureshi, quoted in the Guardian.

"You can very well understand that this is not something that one expects to happen every day and whatever was done it was a spontaneous reaction, actually by the army, to what actions, and wrong action, Mr Nawaz Sharif had taken," a military spokesman, Brigadier Rashid Qureshi, said.

One imagines that US embassy officials in Islamabad, meeting with a reasonable, moderate man such as Musharraf, would have discounted concerns that he had ambitions of ousting a civilian leader like Nawaz Sharif to impose military rule. As the Monitor's Bob Marquand reported, days after the coup, those who knew Musharraf described him as moderate in his religious beliefs, and progressive in his personal habits.

"I would call Musharraf a progressive," says Lt. Gen. Talat Masood, a retired officer. "He believes in equality of education among boys and girls. His daughter is an architect married to another architect, and the marriage was not arranged."

US military attaches and diplomats in Islamabad today must keep a running list of who is who within the Pakistani military, and one assumes they also find many of them to be moderate and progressive, if also increasingly upset at the US for what they see as US interference in Pakistan's sovereignty and national interests. Who among them has the kind of personal loyalty of brigade-level officers that Musharraf commanded in his day? Who among them would lead a coup?

US State Department spokesman Mark Toner was quick to assure reporters on Wednesday that the US has “No concerns and no reason to believe" rumors of an imminent coup in Pakistan. There is no reason to doubt this statement. But with all the ferment in Pakistan’s political environment, it is no assurance that a coup won’t happen.