MAYBE IT WASN'T the best idea to ask the Pentagon to help provide shelter for the homeless. But, if it couldn't do the job, would it have been too much to ask that it give the money back? Apparently, yes.

We're talking about the $8 million that Congress added to the Defense Department budget last year for converting unused military buildings into shelters for homeless people. You might have thought that the department could have scraped the $8 million together from the $265 billion it had on hand to spend this year. But priorities are priorities, and the Pentagon never wanted to be in the shelter-building business anyway. So the $8 million had to come from somewhere else. But did it have to go somewhere else -- somewhere different, that is, from the good works for which Congress appropriated it?

The Army cites many reasons why it never got around to creating the shelters. Advocates for the homeless who originally identified the possibly useful surplus facilities, it argues, didn't understand the Army's need for security, the potential demand for additional space in the event of war (can this be right?), and so on. And only a handful of the hundreds of localities that the Army contacted actually expressed any interest.

Why was that? Perhaps the localities didn't have many homeless or didn't want to attract a large group of transients into their midsts. Perhaps they didn't want to spend their own money on staffing and operating the shelters and other federal aid wasn't available. Perhaps they didn't want to conform to the Army's rules. But whatever the reasons, the fact is that by the end of August the Army had managed to earmark less than $1 million for only two shelter projects.

Now comes the truly piggish part. Rather than let the remaining $7 million go back to the Treasury, the Army decided it desperately needed this money to do more fixing up of Army Reserve facilities.

Why didn't Congress complain? After all, it had specified that the money be spent on the homeless. Well, the Appropriations committees have a lot of faith in the Pentagon's commitment to spend its money wisely. So the Army was fully empowered to divert the money to any of the many, many uses covered by the Army Reserves operations and maintenance account. It was only as a matter of courtesy that the director of the Army budget wrote a letter to the chairman of the House Appropriations Committee telling him that the Army was diverting the money to other -- unspecified, but assuredly important -- purposes. And since the chairman gets dozens of letters from the Pentagon all the time, the letter was passed on to staffers who decided it didn't warrant further attention.

Eight million dollars is only small change for the Pentagon. It's probably barely enough to cover the special election-year public relations campaign that the Pentagon has launched to "win public understanding and support," which will, we trust, supply a reply to this commentary as part of its "active letter-to-the editor program." But $7 million, put into the hands of local agencies and private organizations -- and surely there is some way that could have been done -- could have relieved a great deal of suffering in the coming winter months. Too bad the Pentagon made off with it.