The US Army and Marine Corps are becoming the cripples of the US armed forces.

US ground combat forces are so overwhelmed by insurgencies in Iraq and Afghanistan that they are nearing a point where they are no longer capable of doing anything else. Training, equipment and personnel are all lacking.

Four years after the invasion of Iraq, the high and growing demand for U.S. troops there and in Afghanistan has left ground forces in the United States short of the training, personnel and equipment that would be vital to fight a major ground conflict elsewhere, senior U.S. military and government officials acknowledge.

More troubling, the officials say, is that it will take years for the Army and Marine Corps to recover from what some officials privately have called a "death spiral," in which the ever more rapid pace of war-zone rotations has consumed 40 percent of their total gear, wearied troops and left no time to train to fight anything other than the insurgencies now at hand.

The risk to the nation is serious and deepening, senior officers warn, because the U.S. military now lacks a large strategic reserve of ground troops ready to respond quickly and decisively to potential foreign crises, whether the internal collapse of Pakistan, a conflict with Iran or an outbreak of war on the Korean Peninsula. Air and naval power can only go so far in compensating for infantry, artillery and other land forces, they said. An immediate concern is that critical Army overseas equipment stocks for use in another conflict have been depleted by the recent troop increases in Iraq, they said.

"We have a strategy right now that is outstripping the means to execute it," Gen. Peter J. Schoomaker, Army chief of staff, testified before the Senate Armed Services Committee on Thursday.

Not to mention the fact that, lacking a large strategic reserve, Bush has been using the National Guard on a rotational basis to supplement the manning levels of his Iraq adventure. That means "homeland defence" is also lacking.

But it gets worse. The US military has always maintained pre-positioned, readily deployable equipment to fit-out at least five brigades in the event of an urgent deployment.

The Army should have five full combat brigades' worth of such equipment: two stocks in Kuwait, one in South Korea, and two aboard ships in Guam and at the Diego Garcia base in the Indian Ocean. But the Army had to empty the afloat stocks to support the troop increase in Iraq, and the Kuwait stocks are being used as units to rotate in and out of the country. Only the South Korea stock is close to complete, according to military and government officials.

Then there is the little matter of increased frequency in rotation. Instead of the two-year dwell between rotations, the Pentagon is scrambling to try and keep it at 12 months. In that 12 months out-of-theatre soldiers and marines need to take occupational training, should be involved in at least some field training up to at least one brigade exercise which is not centered on requirements in Iraq and practice personal skills for other environments and combat conditions.

That's not happening. Troops arrive home and within a few months are put back in the training cycle preparing for dealing with an insurgency in Iraq. US troops are losing the versatility to be able to respond to other emergencies.

The increasingly rapid tempo of rotations into Iraq and Afghanistan is also constraining the length and focus of training as active-duty Army combat brigades and Marine combat battalions spend at least as much time in the war zone as at home. As a result, all the training is geared toward counterinsurgencies, while skills important for other major combat operations atrophy.

The Marine Corps is not training for amphibious, mountain or jungle warfare, nor conducting large-scale live-fire maneuvers, Conway said. "We've got a little bit of a blindside there," he said. The Marine Corps and Army both lack sufficient manpower to give troops a break from the combat zone long enough to complete their full spectrum of training, senior officials said.

"We're only able to train them . . . for counterinsurgency operations," Cody told the House panel last week. "They're not trained to full-spectrum operations."

The US Marine Corps has a primary role of amphibious and jungle warfare. So, who does it instead? Nobody.

Under current Army and Marine Corps plans, it will take two to three years after the Iraq war ends and about $17 billion a year to restore their equipment levels. It will take five years and at least $75 billion for the Army to increase its active-duty ranks to 547,000 soldiers, up from the current 509,000, and for the Marine Corps to increase its numbers to 202,000, up from 180,000.

After the Iraq war ends... Those figures are the ones used by the generals if the Iraq war ended tomorrow. With each passing day it gets worse.

But, at least the neo-cons got their war.