Last week the nation's 172 veterans hospitals were mobilized for a role most of the facilities have not played since Vietnam -- caring for wartime casualties.

The Department of Veterans Affairs announced it had "fully activated" for the first time a contingency plan under which its hospitals serve as the primary backup to the Defense Department's smaller hospital system, an assignment Congress gave the VA in 1982. The VA's normal mission is caring for discharged veterans, including those wounded in combat.

Under the support plan, 80 VA hospitals were designated primary care facilities for active-duty personnel who might be injured in any fighting in the Mideast. Most of those hospitals are on the East Coast, but the VA said that all of its hospitals are "potential sites" for injured service personnel.

Twenty-two of the hospitals -- including ones in Washington, Richmond, Baltimore and Martinsburg, W.Va. -- were designated to receive "chemical casualties" in addition to those with conventional wounds, the VA announced. Iraq has used chemical weapons against Kurdish rebels in its own country as well as against Iranians in its long war with that nation. U.S. military officials have expressed concern that chemical weapons might be used against U.S. forces in the gulf.

Under the contingency plan, the department has notified the Pentagon that it could make 9,200 beds available within 24 hours, 18,321 within 72 hours and 25,000 within a month. The Defense Department has 16,000 hospital beds in its military hospital system, compared to 500,000 during World War II, the VA said. Many of those World War II hospitals were converted into VA hospitals after the war.

If a large number of VA beds are required for Middle East casualties, some veterans would be discharged and placed in private hospitals, a VA spokesman said. If the crisis in the Middle East is prolonged and more military reservists are called to active duty, the amount of care the VA could provide might be limited, the official said. Approximately 12,400 of the VA's medical personnel are reservists and 5,700 more are military retirees who could be recalled to military duties, the VA said.

So far, however, the number of VA reservists called to active duty has had "minimal" impact on the hospitals, the VA said.