The excitement over Monday’s resignation of Pakistani President Pervez Musharraf was short-lived. Just a day after he announced he was stepping down, the leaders of the country’s two main parties are already disagreeing and issuing ultimatums as violence continues. The difficulty for the United States and other western countries will be to use economic and military aid to prod Pakistan toward political stability.

While Mr. Musharraf’s departure after nine years of rule was greeted with cheers in Pakistan, who will rule the country and how are unanswered questions. Finding the answers will require working through a complex mix of ethnic loyalties and conflicting motivations.

“Instability is guaranteed,” says Bahman Baktiari, a political science professor at the University of Maine. Another military coup, like the one that brought then-Gen. Musharraf to power in 1999, is also likely.

The difficulty, Prof. Baktiari says, is that Pakistan’s civilian government has little control in a country where ethnic loyalties drive decisions and behavior.

The current point of contention is what to do with the judges whom Mr. Musharraf dismissed in a failed bid to consolidate his power. Nawaz Sharif, the prime minister that Mr. Mussharraf toppled, has threatened to leave the coalition government if the judges are not immediately reinstated. The other coalition leader, Asif Ali Zardari – the widower of slain former Prime Minister Benazir Bhutto – is resisting.

Mr. Zardari opposes the reinstatement of the chief justice, Iftikhar Muhammad Chaudhry, for fear that the justice will pursue corruption charges against Mr. Zardari, head of the Pakistan Peoples Party. Perhaps as important, however, is that the current chief justice, Abdul Hamid Dogar, comes from the province which forms Mr. Zardari’s political base.

Mr. Zardari has presidential aspirations which Mr. Sharif is not likely to allow fulfilled.

The result could be the type of squabbling and inaction that makes strongmen like President Musharraf appealing.

As Ahmed Rashid, a Pakistani journalist, wrote in Monday’s Washington Post, three of Pakistan’s four recent military leaders have been driven from power by popular movements. But the politicians who followed them couldn’t fulfill the people’s desire for democracy and economic development. They were then forced out by the military.

To break this cycle, the United States and the international community must require a more open and effective government that includes the country’s many ethnic groups in exchange for economic aid. Since Sept. 11, the United States has given nearly $12 billion in assistance to Pakistan in exchange for minimal help in combating al-Qaida and the Taliban. During that time, more tribal militias have been formed and radicalization is on the rise.

Because of these many factions, some of which are protecting Osama bin Laden and supporting the Taliban, Pakistan expert Bruce Reidel has called the country the most dangerous in the world.

With so much at stake, the United States and others should put a premium on the creation of an inclusive coalition government that is empowered to address Pakistan’s many problems.