Few residents pay attention to powerful nuclear bombs set off 120 miles away, but an international debate continues as the 40th anniversary of the first blast at the Nevada Test Site approaches.

Only a handful of tests were envisioned when a B-29 dropped the first bomb over Frenchman Flat in the desert northwest of here on Jan. 27, 1951. But there have been 707 tests so far at what now is the only nuclear weapons testing site for the United States and Great Britain.The first atmospheric blast set off burglar alarms in Las Vegas and worried some that the Soviets had blown up Hoover Dam.

Today, weapons with 150 times the punch of the 1951 blast are detonated in shafts at least a third of a mile below the desert's surface. At times the blasts shake high-rise buildings in Las Vegas, 120 miles from ground zero.

Over the years, thousands of anti-nuclear activists have been arrested trying to stop the tests. Most recently, 700 were arrested on trespass charges at a Jan. 5 demonstration.

Critics say the Persian Gulf war points up hypocrisy in U.S. nuclear testing.

"We think it is incredible for President Bush to say Americans face a threat from Saddam Hussein's nuclear potential when they face such a great threat from our own arsenal," said Bill Walker, a spokesman for the Las Vegas-based American Peace Test.

But test supporters say nuclear weapons deterred war between the superpowers and are still needed despite the Cold War's end.

"As long as the policy of this country is nuclear deterrence, we need to continue testing," said Nick Aquilina, manager of the U.S. Energy Department's Nevada Operations Office.

Aquilina sees nuclear weapons as a "peace-establishing device" but admits if they "could be uninvented, we would all prefer that."