Who's winning quiet war in Iraq?

What could rank as one of the least-noticed wars the United States has ever fought may be intensifying.

This week the US ratcheted up its retaliation for Baghdad's near-daily attempts to shoot down American and British jets enforcing the no-fly zones over northern and southern Iraq.

"Pilots have been given greater flexibility to attack those systems that place them in jeopardy," says Defense Secretary William Cohen, explaining they can go after more than the Iraqi defenses that challenge them.

The escalation could mean that the US is now engaged in a conflict of attrition, not just self-defense. With little public notice or complaint from allies, the US has destroyed some 20 percent of Saddam Hussein's anti-air systems in what is now its longest bombing campaign since the Vietnam War.

But with United Nations arms inspectors unlikely to return to Iraq, will munitions be enough to contain Saddam and keep him from threatening neighbors with weapons of mass destruction?

How long the current low-level air war persists and where it is leading remain far from clear. The strategy is replete with risks, including the potential for a politically explosive loss of an allied aircraft.

The new US strategy "may be part of a desire to increase the costs to the regime in hopes it will cease and desist its efforts to challenge us and the Brits," says Zalmay Khalilzad, a former senior Pentagon official now with the RAND Corp., a think tank. "But there is this question of how long we can sustain this."

Mr. Cohen will likely face that and other questions about Washington's intentions during an eight-day Middle East trip he begins today. Some Western allies and the Arab League have called on the US and Britain to halt their strikes. But that would hand Saddam a major political victory, boost his prestige in the Arab world, and eliminate one of the few sources of leverage Washington has with the Iraqi dictator.

A day after hitting an Iraqi oil-pumping facility, US F-15 jets on March 1 unleashed their heaviest counterattack in more than 100 clashes in the no-fly zones over the past six weeks. Reacting to antiaircraft and missile fire that posed little threat, they hit Iraqi targets in the northern no-fly zone with more than 30 laser-guided bombs.

The development put Iraq back in the headlines, serving as a reminder that the US and Britain have been in an undeclared war since Saddam responded to the December airstrikes by saying he would no longer respect the no-fly zones. He is offering his troops bounties for downing an allied jet and capturing a pilot.

His aim, experts agree, is to weaken political support in the US and Britain - especially if an allied aircraft is lost - for what seems to be a confrontation without end. He also hopes to keep international attention riveted on his demand for the lifting of UN sanctions that has prevented him from rearming his military and reduced many of his 21 million people to penury.

Some experts believe the intensified US retaliation is intended to accelerate the "erosion" of Iraq's defenses as part of a long-term strategy to weaken Saddam's grip on power and encourage a coup by dissident military officers.

These experts point out that the harsher US counterattacks follow reports of unrest in Baghdad and southern Iraq ignited by the Feb. 18 murder of the chief cleric of Iraq's Shiite Muslim majority, long oppressed by the minority Sunni-dominated regime. The southern no-fly zone was created to protect the bulk of Iraq's restive Shiite population. "There certainly is an awareness that the signs of unrest and uncontrollable activities are increasing," says a US official. "It is entirely possible that we are beefing up ... in response to growing unrest in Iraq."

Other US officials say the new tactics simply reflect growing Iraqi breaches of the no-fly zones and attempts to down allied aircraft. "He [Saddam] is shooting at our planes and we are responding," says a senior Pentagon official.

Other experts see the harsher US response differently. They say Iraq has moved most of its prized Russian-made antiaircraft missiles into central Iraq, forcing allied aircraft to expand the list of high-value targets against which to retaliate. Furthermore, they say, the Pentagon is anxious to avoid the loss of an aircraft. Therefore, US jets are going after more targets on the edges of the no-fly zones.

The new strategy may also have domestic political benefits for Clinton by deflecting some GOP heat he is under to implement the Iraq Liberation Act. The act, which he signed late last year, gives him up to $97 million to finance an insurrection against Saddam by opposition groups.

Clinton last month designated seven groups to receive arms and training, and appointed a special coordinator to oversee the effort. But he has drawn GOP ire for declining to dispense the funds amid skepticism over the Iraqi opposition's cohesion and ability to oust Saddam.