In his last speech as Pentagon Chief, Defense Secretary Robert Gates delivered some harsh words about NATO, saying it could soon become irrelevant if other countries don't offer more support to its largely U.S.-dominated operations, according to the Associate Press. 

Defense Secretary Robert M. Gates addresses the National Guard's 2009 Joint Senior Leadership Conference (via Creative Commons

Gates said the U.S. is growing tired of having to supplement NATO's military actions as other nations in the alliance slash defense budgets. U.S. politicians and voters "losing their appetite" for their country's ever-increasing role in world security, he said.

"Despite more than 2 million troops in uniform, not counting the U.S. military, NATO has struggled, at times desperately, to sustain a deployment of 25,000 to 45,000 troops, not just in boots on the ground, but in crucial support assets such as helicopters, transport aircraft, maintenance, intelligence, surveillance and reconnaissance, and much more," Gates said.

This comes just after reports that the international community has pledged an additional $1 billion to fight strongman Muammar Gaddafi's forces in Libya. Gadaffi himself may now be a target in the NATO operations, which were originally proposed as protection for civilian rebels.

Gates cited the war in Libya as an example of the imbalance in NATO strategy: 

"The mightiest military alliance in history is only 11 weeks into an operation against a poorly armed regime in a sparsely populated country, yet many allies are beginning to run short of munitions, requiring the U.S., once more, to make up the difference," he said.

U.S. commentators have long criticized NATO's operations as being "international" in name only. The war in Libya, argued Real Clear Politics' David Paul Kuhn, is a U.S. war, even though President Obama declared emphatically that it would not be American-led.

Indeed, the French were the ones who led the push for intervention against Gaddafi's brutal regime, but, as Kuhn pointed out, 122 of the first 124 Tomahawks fired were fired by American forces.

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