Twenty feet long, stealthy, and fast, they streak under enemy radars as they hug the terrain on their way to targets as far as 1,000 miles away.
Relatively cheap at some $1 million each, they can be fired from planes and ships. Bearing single warheads or clusters of bombs, they are designed to land within feet of their targets. They can carry nuclear payloads.
With the United States moving toward another clash with Iraq over United Nations arms inspections, 300 Tomahawk cruise missiles aboard American ships in the Gulf are certain to play a major role in any airstrikes, just as they did in the 1991 Gulf War, when they were first fired in combat.
Their use, experts say, will be in keeping with a trend in which the US has increasingly come to rely on non-nuclear versions of these missiles - which keep US forces largely out of harm's way - as instruments of foreign policy. Yet there are concerns about the potential for political leaders to become too dependent on the weapons as levers of foreign policy.
Cruise missiles have allowed President Clinton to make good on threats to use force while avoiding American casualties in crises where the nation's security is not immediately endangered.
A cruise missile "is a very attractive tool for forceful diplomacy because it gives you the ability to have influence over a certain area without suffering exposure to casualties and without the great risks of collateral damage," says Barry Posen, who teaches national security strategy at the Massachusetts Institute of Technology in Cambridge, Mass.
Agrees John Hillen, a Washington-based defense expert at the Council on Foreign Relations, a think tank: "We will see more use [of cruise missiles]. They are an attractive option for anyone in politics. [Their use] makes it appear to your constituents as if you have taken decisive military action."
An inadequate substitute?
But the danger arises, these experts and others say, from the post-cold-war reluctance of US politicians to risk lives and money overseas, the operational strains on a downsized US military, and a need to maintain the credibility of American power. The missiles, they say, could become substitutes for addressing threats that can only be removed through massive force, they say.
"There is not a single instance where the use of cruise missiles alone or even in concert with other airstrikes have actually delivered a political solution, which is the only reason you use military force in the first place," says Mr. Hillen. "It's just a feel-good, no-cost, some-PR-yield option."
In other words, he and others assert, the cruise missile - first produced by the US in the early 1980s to protect its strategic bombers in a nuclear war with the former Soviet Union - has become emblematic of Clinton's periodic run-ins with Iraq: It does damage, but does not remove Saddam, widely viewed as the main threat to the stability of the world's chief oil-producing region.
Used on Serbs, Bin Laden
There is no dispute that the missiles have enormous tactical uses, like taking out key stationary targets. They can also be used to reach terrorists sheltered in far-off, inhospitable countries.
Responding to the Aug. 7 US Embassy bombings in East Africa, Clinton ordered cruise missiles lofted two weeks later into training camps in Afghanistan run by the alleged mastermind of the attacks, Osama bin Laden.
The US also fired them at a Sudanese pharmaceutical factory it claimed was linked to the Islamic extremist.
Clinton also authorized an attack in 1993 by 23 cruise missiles on the Baghdad headquarters of the Iraqi intelligence services for allegedly plotting to assassinate his predecessor, George Bush. Earlier that year, the US launched cruise missiles at a suspected Iraqi nuclear facility and in 1996, fired them again at Iraqi air defenses after Saddam Hussein sent his troops against Kurdish rebels in northern Iraq.
"As a weapon of punishment, especially where the damage should be limited, they [cruise missiles] do serve a useful purpose," says former senior Pentagon official Zalmay Khalilzad of the RAND Corp., a think tank.
The missiles have powerful psychological impacts. US envoy Richard Holbrooke, in his memoir on brokering peace in Bosnia in 1995, says that 13 fired at the Bosnian Serbs helped drive them to the negotiating table.
Yet the effectiveness of cruise missiles in attaining strategic goals, such as eliminating Saddam, is unproven, and dismissed by many experts.
Current models cannot penetrate hardened targets or hit moving vehicles; they have never forced entrenched foes to surrender territory; nor have they ever eliminated terrorist groups, enemy leaders, or their regimes.
"We seem to think we can use them as a strategy in and of themselves, rather than a strategic tool," says Hillen. "But they are like one golf club in a bag of clubs."
Furthermore, these experts say that by threatening to fire cruise missiles as the US recently did against Serb forces in Kosovo, or using them too often, Washington conveys weakness, confirming to adversaries its reluctance to commit ground forces to costly, long-term fights.
"This is a dangerous trend," says Michael O'Hanlon, a defense expert at the Brookings Institution, a Washington research institute. "It shows ... that our interests are not that great and it means we are not willing to use our own troops, which means we won't risk escalation."
It is because of these drawbacks that he and others dispute forecasts of increasing US reliance on cruise missiles as foreign policy tools.
"The reason you cannot say that this will continue for a sustained period is that the success record of the missiles is minimal," says Dov Zakheim, a former senior Pentagon official. "A few more failures and we are going to have to reevaluate this approach."
"In this new era, most of the problems we face are problems of limited stakes for the US," says Dr. Khalilzad. Aside from contributing to conventional military operations, he say, cruise missiles will be used increasingly "in situations where we decide that doing something is better than doing nothing."