The U.S. has passed a sad milestone in Iraq. The news media have had stories ready for days: "4,000th U.S. death in Iraq." And Americans should mourn every one.

Death strikes the armed forces, even in peacetime. In 1980, for example 2,392 active duty personnel died, most in accidents, but also from illness, homicide and suicide.

In the first five years of the Clinton administration, U.S. active duty military deaths totaled 5,119, a thousand more than the first five years of the Iraq war. Only one was from hostile action.

Yet politicians didn't howl about the death toll. TV commentators were silent as the 4,000th and 5,000th deaths were recorded. Activists didn't make demands.

There were headlines, sometimes -- usually small ones -- buried in the back pages. "Navy jet feared lost." "Two die in truck crash on Marine maneuvers." "Authorities investigate slaying of soldier."

Are these non-combat deaths somehow easier to accept? Of course. Combat deaths are viewed differently because (depending on your politics) they "didn't have to happen." Blame is assignable to political leaders.

Karl von Clausewitz was right when he said that war is politics by other means. And so the political objectives of war -- and the politicians who push them -- are properly subject to the roiling waves of domestic opinion.

Certainly, the politics of war are complex; and there are always detractors. Even World War II had its critics and pacifists. Only in hindsight do we all agree that the decision to go to war was correct in 1941. There are simply times that the consequences of avoiding war are worse than the consequences of war itself.

That may be the case with worldwide terrorism. The question is not the number of deaths but the purposes achieved. If the Iraq war helps to keep terrorists off our soil -- and by unseating Saddam Hussein it has, according to a detailed report by the Institute for Defense Analyses -- then it might be seen as a responsible move.

Life in the Army, Navy, Air Force and Marine Corps is always dangerous. Pilots land airplanes on ships at sea. Helicopters fly at night over rough terrain. Soldiers train with machine guns loaded with live ammo. Sometimes they just drive fast on bad roads or live in unsanitary conditions. And service personnel are largely young men, who tend toward risky behavior whether or not they're wearing a uniform.

Every year hundreds of young men and women will lose their lives in service of our country -- and will do so whether we are in Iraq or not.

We do not downplay the sacrifices made in combat. Accidents are quite different from deployment in places where an enemy is actively trying to kill you. Still, it's good remember that everyone in uniform is risking his or her life, whether in Anbar Province or up at Hill Air Force Base.

The scope of the losses in Iraq, while heart-wrenching, should not be measured against an impossible ideal in which service personnel are invulnerable. It should be measured against the risks we ask our men and women in uniform to take every day in war and peace.

More important, the losses in Iraq must be measured against gains. Yes, the Iraq war has seen blunders and tragedies; so does every war. It has also unseated a murderous tyrant, pushed another to give up nuclear weapons, and sent a fair number of fanatics to an early and well-deserved grave. It has also raised the hope that Iraq can become a foothold for democracy and a beacon of hope in the Mideast.

The best way to honor the 4,000 fallen is to do all that can be done to help their mission succeed.

As President Bush just said, "One day people will look back at this moment in history and say, 'Thank God there were courageous people willing to serve, because they laid the foundations for peace for generations to come.' I have vowed in the past, and I will vow so long as I'm president, to make sure that those lives were not lost in vain."

That is not just the president's responsibility, but also our own.