Some veterans of the Vietnam War still express surprise at the unfriendly receptions they received when they returned to the United States from that combat zone. But they could have predicted that many of them would end up on the streets within a few years of arriving back home. Chronic homelessness has been a cruel reality for veterans since at least the Civil War, when former fighters who hit hard times took the nickname "tramps," after the sound they made when they had marched into battle years earlier.

That sad history gives the nation a heads up today as veterans come home from Iraq and Afghanistan. Many will struggle with homelessness: the U.S. Veterans Affairs Department already has identified 1,500 vets from the current wars who have joined others who sleep under bridges and in lonely patches of woods. As with many homeless people, homeless veterans suffer disproportionately from mental illnesses. And they also often deal with drug and alcohol problems.

Extensive advances in the understanding of post-traumatic stress syndrome help doctors treat veterans shocked by war, and deficiencies uncovered at Walter Reed Army Medical Center last year at least put combat veterans' needs on the front burner in Washington.

Veterans' advocates are right to push now for services, including affordable housing for those returning from war zones. The U.S. Department of Housing and Urban Development is making an impressive effort at lowering homelessness nationally, and some of what it is learning ought to be applied specifically to veterans.

Congress, of course, needs to put spending to ease the transition for veterans high on its priorities as those troops come home, including making sure there's a home for them when they get here.