Proliferation of cruise missiles Sparks concern about U.S. air defenses.

• Author: Erwin, Sandra I.

The Pentagon calls them, euphemistically, "asymmetric" weapons. The U.S. military fears them because they sneak into blind spots.

The wars in Iraq and Afghanistan saw the rise of improvised explosive devices as the ultimate asymmetric weapon. Future conflicts, strategists warn, could expose U.S. forces on land and at sea to a deadly weapon that is extremely hard to detect: cruise missiles.

"They are a very tough threat to deal with," said Philip Coyle, senior science fellow at the Center for Arms Control and Non-Proliferation. The Pentagon for years pretended cruise missiles did not exist," he said. "The Defense Department does not know how to defend against them."

Cruise missiles have been nicknamed a "poor man's air force" as they could potentially undercut the military advantage of a much more powerful adversary such as the United States.

Coyle, who served as the director of weapons testing at the Pentagon during the Clinton administration, said his office used to worry about U.S. air defenses against cruise missiles. "They fly low, they don't travel in a straight line, they can avoid radar detection," he said. They are just as dangerous for troops on the ground as they are for ships at sea, Coyle said.

While in charge of the testing office, Coyle sought to buy Russian sea-skimming supersonic cruise missiles so they could be used as targets against U.S. air defenses. "The Russians didn't want to sell them to us," he said. "The Chinese have similar capabilities."

The United States does not expect to be going to war against China or Russia, but the U.S. could in the foreseeable future have to fight other nations or non-state groups that are able to acquire missiles from those two powers.

"The concern is not [only] about what China and Russia are building for their own militaries but what they are willing to transfer or willing to give to proxies," said Andrew Krepinevich, a military analyst and president of the Center for Strategic and Budgetary Assessments. "Hezbollah is not building its own anti-ship cruise missiles or drones. They are getting them from somewhere else," said Krepinevich, referring to the Islamist militant group in Lebanon that has launched missiles against Israel.

The guidance technology available for cruise missiles will advance rapidly in the coming decade, said a study by the U.S. Air Force's National Air and Space Intelligence Center.

"Defending against land-attack cruise missiles will stress air defense systems," said the report. Most missiles fly at low altitudes to stay below enemy radar and, in some cases, hide behind terrain features. But newer missiles are incorporating stealth features to make them even less visible to radars and infrared detectors, said the NASIC report. Modern systems also can be programmed so multiple missiles can attack a target...