After more than a decade of continuous warfare, the cost of disability compensation for wounded veterans is surging to mammoth proportions.

The U.S. Department of Veterans Affairs expects to spend $57 billion on disability benefits next year.

That's up 25% from $46 billion this year, and nearly quadruple the $15 billion spent in 2000, before the wars in Iraq and Afghanistan began.

About 4,500 U.S. troops were killed in Iraq and about 1,800 have been killed in Afghanistan.

Some 633,000 veterans, one out of every four of the 2.3 million who served in Iraq and Afghanistan, have a service-connected disability, according to the Bureau of Labor Statistics.