By Will Dunham

WASHINGTON: Five years of warfare in Iraq and Afghanistan have left signs of wear and tear on the US military, raising questions about its ability to sustain its current level of operations and confront potential new crises.

The US-led invasion of Afghanistan, ordered following the September 11 attacks, began on October 7, 2001, thrusting the all-volunteer US military into combat that has continued unabated there and, since March 2003, in Iraq.

Senior military officers, including Army Chief of Staff Gen. Peter Schoomaker, have warned of falling combat readiness of some units and mounting equipment shortfalls, with Abrams tanks, Bradley Fighting Vehicles and other equipment battered from extended use on the battlefield.

Many troops are facing second and third long combat tours and less time between overseas deployments. At the same time, the US death toll mounts, with more than 2,730 troops killed in Iraq and about 280 more in Afghanistan.

"We’re in the early stages of some sort of crisis that, if not addressed, will result in breaking the force," said retired Army Col. Andrew Bacevich, a military expert at Boston University.

"You’d have to be remarkably naive to think that we’re going to be able to continue to place this level of stress on the force for all that much longer."

This is the first time since the draft ended in 1973 that US forces have been tested by protracted warfare.

Lexington Institute defence analyst Loren Thompson said the Navy was the only service in genuinely good shape in a military of 1.42mn active-duty troops and 830,000 part-time reserves. "The ground forces – the Army and the Marine Corps – are in a very rundown and beleaguered state. And the Air Force’s fleet of aircraft has become almost archaic, they’re so aged," he said.

Pentagon officials defend the condition of the military.

"We are a nation at war," said Pentagon spokesman Bryan Whitman. "The armed forces of this nation are not only up to the task, they are performing their missions superbly." The military has struggled to maintain troop levels of 141,000 in Iraq and 21,000 in Afghanistan. For example, it has had to postpone the scheduled departure of two 4,000-strong Army combat brigades from Iraq and accelerate the deployment of a third.

With the Army and Marines stretched thin, the Pentagon has converted thousands of Navy and Air Force personnel into ground troops to do jobs like driving trucks and guarding detainees.

A major concern for the US top brass is the military’s ability to respond if hostilities broke out in another hot spot such as Iran or North Korea.

With the Army and Marines tied down in Iraq and Afghanistan, the Navy and Air Force might have to carry the load, meaning air-strikes and naval blockades rather than a big commitment of ground forces.

A broad mobilisation of hundreds of thousands of National Guard and Reserve personnel also might be deemed necessary, but such a move risks a backlash from US communities from which part-time troops would be plucked from civilian lives. The Pentagon already has made heavy use of them. As recently as last year, they made up 40% of the Iraq force.

The Army has compelled 75,000 soldiers, including 11,000 currently, to continue serving after their voluntary stints ended, under a policy called "stop loss" intended to keep units designated to go to Iraq and Afghanistan fully manned. Some soldiers can be forced to stay in the Army an extra 18 months, a practice some critics in Congress call a "backdoor draft." Brookings Institution defence analyst Michael O’Hanlon noted other signs of stress on troops, including rising divorce rates and suicides and the departure of mid-level officers. "I think morale is very fragile right now and in danger of getting a lot worse very soon," O’Hanlon said. – Reuters