50 Military Vehicles Missing at U.S. Base : Losses: Some officers fear they could be used to disguise a terrorist attack. Others say it may be just cannibalization by GIs short of supplies.

In a rash of thefts that have raised concerns about a possible terrorist attack, at least 50 American military vehicles have disappeared in the last several weeks from a forward-based facility used by the U.S. Army here, according to senior officers.

The almost nightly losses of five-ton trucks, Humvee jeeps and other distinctive Army vehicles from within the apparently secure military compound have left the officers troubled at the prospect that terrorists might attempt to pose as U.S. soldiers in launching an attack on military camps or other facilities.

One officer said Friday that despite an extensive investigation by U.S. Military Police and other authorities, none of the vehicles has yet been found.

The mounting toll of vanishing vehicles assigned to units throughout the theater comes in the wake of intelligence reports issued to commanders in the second week of the war warning that more than a dozen Palestinian terrorists are known to be operating in the sector now occupied by the 1st Armored Division.

In response, sentries posted on the perimeter of American camps scattered across the desert have been warned to be extra vigilant in watching for “foreign nationals” driving civilian vehicles and behaving in a “suspicious manner.”

With hundreds of ammunition trucks, tankers and other types of military vehicles crisscrossing the flat, barren terrain every hour, the specter of an attack launched in a U.S. vehicle has added to commanders’ worries.

Some officers have discounted the idea that the thefts are terrorist-related. They believe that U.S. soldiers may be stealing the vehicles because of shortages of vehicles and spare parts in units whose supplies have not yet been delivered to their desert base camps.

“Some of these guys are having trouble keeping their vehicles going,” one intelligence officer said. “The way I look at it, this is cannibalization pure and simple.”

“The supplies that were short are still short,” another officer told colleagues recently, referring to still-inadequate stocks of items such as maps and chemical protection suits for which urgent requests were submitted more than 10 days ago.

Some Army divisions here are still awaiting replacements for the chemical suits used Jan. 17 when Iraq fired its first Scud missiles in response to the U.S. aerial attack on its territory. Soldiers were told before the war that the suits would begin to lose their effectiveness two weeks after being removed from sealed pouches. With the spares not yet distributed, however, they are now being told that the suits can remain effective as long as 30 days after they are opened.

But most officers here said that possible terrorism is still the leading theory for the rash of mysterious thefts from a sprawling Saudi base about two hours from here that is now dominated by the U.S. Army and Air Force. Such a scenario was described by one senior officer as “a real nightmare.”

The officers stress, however, that they believe security measures against such a raid are adequate.

These steps have transformed this section of the desert, populated until 45 days ago only by local Bedouins, into a virtual American military security zone.

For a time, military police and sentries were under orders to stop any “foreign national” driving through the Army division’s area of operations, officers confirmed. Those orders were modified early last week, however, after a local police officer was detained for several hours when MPs who stopped and searched his vehicle found a suitcase full of cash.

The man was allowed to proceed with apologies after his identity was established, officers said, and the U.S. military security personnel are now authorized to detain only those behaving in “a suspicious manner.”