ISLAMABAD, Pakistan - Pakistan's U.S.-allied ruling party suffered a fresh blow to its fragile hold on power Tuesday when a coalition partner said it would quit the cabinet, deepening the nation's political turmoil and potentially distracting Islamabad from helping U.S. forces target insurgents.

New elections could lead to the emergence of a government not as friendly to U.S. interests and less vocal in opposing the Taliban.

Still, even if the government changes - a prospect that is not at all certain - the country's new leaders would be faced with the same seemingly intractable challenges: a feeble economy, chronic power shortages, and rebuilding after this year's horrendous flooding.

And they will have to navigate the delicate partnership between their military, the nation's most powerful institution, and the United States, which provides billions in aid, to target al-Qaeda and Taliban fighters who use Pakistani territory to plan attacks on Western troops in neighboring Afghanistan.

The current government "is not only too weak to meet the U.S.'s short-term priorities even if it wanted to; it's already too weak to meet the long-term priorities that would give Pakistan stability," said Anthony Cordesman, an analyst for the Center for Strategic and International Studies in Washington.

The stability of a nuclear-armed Pakistan is a higher strategic priority for the United States than the future of Afghanistan, Cordesman said. If Pakistan came under Islamist extremist rule, it would be far more threatening as an al-Qaeda sanctuary than Afghanistan ever could be, he said.

Tuesday's decision by the Muttahida Qaumi Movement to leave the cabinet showed the willingness of members of the governing coalition to challenge the unpopular, ruling Pakistan People's Party.

The MQM, a secular party with its power base in the southern port city of Karachi, said it would pull its two ministers, though it insisted it was not yet joining the opposition. The move came days after the Jamiat Ulema Islam announced it was leaving to join the opposition.

Analysts said the two parties were aware of the PPP's unpopularity and were positioning themselves for potential early elections.

The PPP won the most seats in 2008 elections weeks after its leader, Benazir Bhutto, was assassinated. Her widower, Asif Ali Zardari, won the presidency months later after forcing former military ruler Pervez Musharraf to quit the post.

But enthusiasm for the PPP-led government has faded as Pakistan's problems have worsened.

The country's economy is subsisting on $11 billion in loans from the International Monetary Fund. Electricity shortages plague homes and businesses. The massive floods of 2010 only made things worse.

Despite several army offensives, Islamist extremists still sow chaos in the country. The government has struggled to reestablish local administrations in regions where the army has pushed out the extremists.

And the United States is still using drone-fired missile strikes against extremist targets in Pakistan's tribal regions, a practice that has enraged many Pakistanis.

Still, both parties could patch up differences with the PPP if they get some concessions. Zardari's party was lobbying Tuesday to prevent the MQM from leaving the coalition.

3 Missile Strikes Kill 17 in Pakistan

Three suspected U.S. missile strikes targeting an extremist-riddled Pakistani tribal region near the Afghan border killed 17 people Tuesday, including at least two who were retrieving bodies from the first attack, Pakistani intelligence officials said.

The strikes come in the final days of a year

that has seen an unprecedented number of drone-fired attacks as part of a ramped-up U.S. campaign to take out al-Qaeda and Taliban fighters seeking sanctuary outside Afghanistan.

About 115 missile strikes have been launched this year - more than double last year's total. Nearly all have landed in North Waziristan, a region that hosts several insurgent groups battling U.S. and NATO troops in Afghanistan, including the feared Haqqani network.

Pakistan officially protests the strikes, saying they violate its sovereignty and anger tribesmen whose support it needs to fend off extremists. But Islamabad is widely believed to secretly support the strikes.

- Associated Press