The U.S. military has now made over 2 million individual deployments to Iraq and or Afghanistan. The preponderance, of course, has been our "ground-pounding" soldiers and Marines - many on multiple tours.

This high ground-force operational tempo ("ops tempo") has led some to declare our military nearly broken, incapable of handling another major conflict - that is, lacking in what military planners call "strategic depth."

Legit concerns. But we're not at "mission impossible" - yet.

Yes, our active-duty and reserve ground forces are tired - and understandably so. So is their equipment after four years of wear and tear in combat in Iraq and Afghanistan.

Army Chief of Staff Gen. Peter Schoomaker has issued strong warnings to Congress about repeat deployments and their toll on the army's health and welfare. The Marines, ever reluctant to complain, concur.

The Army/Marine ops tempo should give us pause. But that doesn't mean Uncle Sam can't handle another fight if necessary - thanks to the Navy and Air Force.

Sure, it would be tough, but let me explain:

Outside of Iraq/Afghanistan, the three conflicts most likely to involve America are a strike on Iranian nuclear facilities, a China-Taiwan dust-up and another Korean-peninsula war.

Not minor military matters, but with the arguable exception of Korea, they could all be fought using heavy doses of sea and air power, which, fortunately, aren't stretched as thin as our ground forces.

Iran: An attack would likely be executed by U.S. air and sea strikes, not ground forces (but don't count out special ops).

Air Force B-2 bombers and F-117, F-15 and F-16 strike fighters would drop GPS-guided JDAM and gravity bombs on Iranian air defenses, nuclear facilities and retaliatory forces such as the Islamic Revolutionary Guard Corps.

The Navy would chime in with carrier-based aviation and surface ships/submarines in the Persian Gulf and the North Arabian Sea, dropping bombs and firing cruise missiles at Iran's nuclear sites, air defenses and naval assets.

China-Taiwan: While the chance of a conflict across the Taiwan Strait is remote, China's defense buildup and recent Taiwanese rhetoric about "independence" keeps this possibility at the front of war planners' minds.

Fortunately, a Chinese attack on Taiwan must navigate the 100-mile-wide Taiwan Strait. China doesn't have the air- and sea-lift capability to support a full-scale invasion of Taiwan - so it would have to rely on ballistic missiles and sea and air power.

The U.S. objective would be to protect the political status quo, using air and naval forces to break Chinese naval blockades, counter air or missile strikes and vanquish sea- or airborne invasion forces as they cross the strait.

Korea: A Korean contingency would normally call for significant U.S. ground forces. But the 28,000 American and 650,000 South Korean troops now "in country" could fight a holding action until the U.S. cavalry - forces not deployed to Iraq, Afghanistan or the Persian Gulf - arrived.

South Korea's ground forces alone are more than a match for the North Korean People's Army - which, while still dangerous, is a shell of what it was back in the days when Pyongyang was getting military aid from the Soviet Union. The United States would quickly add naval and air assets to throw the fight in our direction.

Missile defenses are already deployed for dealing with North Korea's long-range missile and nuclear capability. These - and theater missile defenses - are constantly being developed and improved.

But, while the Navy and Air Force can respond, we shouldn't feel comfortable with the way things stand. We're looking down the barrel of a "hollow force" if trends in defense spending and ops tempo for all services don't change.

The Army and Marines are finally adding troops after 1990s cutbacks. But at the same time, the Navy and Air Force are cutting personnel in a "rob Peter to pay Paul" strategy to finance needed weapons systems.

It's hard to believe, but U.S. defense spending remains at historic lows as a percentage of gross domestic product, despite the large budgets since 9/11. This isn't good for our national security - or fair to our fighting men and women. It's encouraging to adversaries.

There's plenty of blame to go around. Finger-pointing makes for good political sport, but fixing the problem instead of assigning blame is what counts. Congress needs to act quickly. Raising and maintaining our armed forces is its constitutional duty. Anything less than giving our military the wherewithal to take on the challenges to our national security is unacceptable - and dangerous.

Peter Brookes is a columnist forThe New York Post, a Heritage Foundation senior fellow and author of "A Devil's Triangle: Terrorism, WMD and Rogue States."