The Senate, sidestepping a proposal to impose the death penalty for drug-related murders, passed a $299.5 billion defense bill Friday that orders the U.S. military into the war on drugs.

The bill also would establish a fast-track procedure that could lead to the closing of obsolete U.S. military bases in every part of the country.The Senate approved the bill by voice vote and sent it to the House, which earlier passed a bill with the same $299.5 billion total. But the many differences in the two bills on how the authorized money will be allocated still must be resolved by Senate-House negotiators.

The bill, which was ready for passage May 17, was blocked when Sen. Alfonse D'Amato, R-N.Y., refused to drop an amendment dealing with the death penalty, despite threats of a filibuster against it by opponents and entreaties from Senate leaders.

The conservative D'Amato, whose amendment has broad support in the Senate, finally succumbed to a week-old offer assuring him consideration of his provision as a separate measure beginning June 8.

D'Amato's death penalty proposal calls for capital punishment for drug-related murders, for narcotics kingpins who order killings and for drug suspects who kill policemen.

It also would apply to anyone who killed a U.S. serviceman involved in the military's anti-drug efforts.

The huge Pentagon spending package for fiscal 1989 marks the fourth straight year of declining defense budgets, which peaked at $334 billion in fiscal 1985. After allowing for inflation, the 1989 figure is down 11 percent from 1985. Last year's figure was $291.4 billion and inflation adjustments make the 1989 number just less than a 1 percent decrease from 1988.

The Senate and House bills give the United States a leaner military, due to budget constraints.

Two Air Force fighter wings would be deactivated, overall troops strength would drop about 36,000, which would still keep total manpower at 2.1 million, the activation of several Army units will be delayed, and hundreds of Army helicopters will be mothballed early, as will 16 Navy frigates.

One of the major struggles faced by the House-Senate conference will be resolving the different proposals for involving the military in the war on drugs.

The more limited Senate bill boosts the Pentagon's surveillance of smugglers, increases the command and communications role and gives the Navy power to make arrests.

The House bill, however, would involve the military more deeply by ordering the Pentagon to seal the U.S. borders within 45 days and prevent drugs from being smuggled into the country.

The politically sensitive base closing provision, which is certain to have a severe economic impact in many communities, is the first major effort since the mid-1970s to shut down obsolete bases. But the measure does offer assistance to affected communities.