NATO envoys failed on Wednesday to agree to take command of the U.N.-authorized military operation in Libya, Reuters reports, after days of disagreement about who should lead the mission once the U.S.--already stretched thin in Iraq and Afghanistan--cedes control.

The news comes after a British commander declared that Muammar Qaddafi's air force "no longer exists as a fighting force," and that the coalition was now targeting Qaddafi's ground forces, suggesting that the coalition had already achieved part of its mission. And indeed, Western warplanes spent the day attacking Qaddafi's artillery and tanks near the western town of Misrata, which has been the scene of heavy fighting between government and opposition forces.

The NATO talks primarily fell apart over Turkey's opposition to the coalition's air strikes, which it believes go beyond the U.N. mandate for a no-fly zone and risk civilian casualties. Reuters explains that Turkey--"a Muslim NATO member with big business interests in Libya"--may want Western coalition countries to conclude the strikes before NATO takes command. "It would be impossible for us to share responsibility in an operation that some authorities have described as a 'crusade'," Turkish Foreign Minister Ahmet Davutoglu told reporters, referring to the term both Qaddafi and Russian Prime Minister Vladimir Putin have used to describe the operation.

France, meanwhile, worries that a NATO-led mission might alienate the Arab world and wants the coalition to share political control instead. The U.S., U.K., and Italy support NATO taking command. NATO would need the support of all 28 members of its alliance to seize the reins of the operation. In the meantime, NATO ships have begun patrolling off the Libyan coast to enforce the U.N.'s arms embargo against Qaddafi's regime.

U.S. Defense Secretary Robert Gates also said today that the U.S. could turn over control of the military operation as soon as Saturday, according to the Associated Press. But that deadline's probably ambitious, Reuters notes, given that NATO needs 72 hours to implement whatever decision it ends up reaching.