Washington ? Prewar jitters are here, and military minds are trained not only to make sure everything goes right but also to know all that could go wrong.

Defense Secretary Donald Rumsfeld, a known worrywart, has talked for months about a list in his desk that outlines the risks of using military force against Iraq. It’s been growing.

“I wish we were wise enough to think of all the things that could go wrong,” Rumsfeld says. “There’s always the risks of acting, and there are also the risks of not acting.”

Other senior officials in the Bush administration have been circumspect about the downside. President Bush himself has turned aside questions about dark scenarios and war costs, saying the price of doing nothing surely would be worse.

Rumsfeld frets.

His list, which he says is already four to five typewritten pages long, is being revised constantly: Iraq could unleash chemical or biological weapons, attack its neighbors, blow up its oil fields, engage U.S. soldiers in close-in fighting in “fortress Baghdad.”

“It goes on and on,” he said, tracing the things that could “make life very difficult.” He’s even been worried about the possibility of flooding in Iraq.

It’s not unusual for Rumsfeld to write down his worries; many military leaders in crises keep a running tab of things that could cause problems, says Jay Farrar, a 22-year veteran of the Marines who has held legislative affairs posts at the Defense Department, White House and Joint Chiefs of Staff.

“I don’t know if he sleeps with it at night,” Farrar said of the list. Rumsfeld is “a worrywart, but not like somebody who’s chewing their nails about things and can’t sleep. He’s the kind of person who is just constantly working on details.”

To be sure, Rumsfeld is no nay-sayer when talking about an attack on Iraq. “There are also a number of things that can go right,” he said in a recent broadcast interview.

Topping Rumsfeld’s list is his concern that Iraqi President Saddam Hussein could use weapons of mass destruction.

“If force has to be used, and Saddam Hussein’s regime decides that the game is up, they could conceivably use chemical or biological weapons,” he said. “They could use them on U.S. forces or coalition forces in neighboring countries or in Iraq. They could also use them on their own people and blame it on the coalition forces, which they’ve done before.”

Rumsfeld seems to be the only Bush administration official wearing his worries on his sleeve.

Bush has received an array of cost estimates on a possible war, but he has decided not to share them with the public. He says the estimates will come to light after war starts — if he chooses war — when he asks Congress for the money to finance it.

Rumsfeld says he has shared his list with the president and the National Security Council. It’s grown from 3 1/2 to four or five pages with additions by the deputy defense secretary, Paul Wolfowitz, as well as the Joint Chiefs chairman, Air Force Gen. Richard Myers, and Myers’ top deputy, Marine Gen. Pete Pace.

The White House might be happy that Rumsfeld has gone public with details of his list, suggests Farrar, now a foreign affairs specialist for the Washington think tank the Center for Strategic & International Studies.

“I don’t think the White House was upset,” Farrar said. “It shows a very prudent thought process — that everybody is not absolutely, overwhelmingly confident that everything is going to go as clockwork.”