Washington -- The Pentagon's top brass stood shoulder to shoulder yesterday to defend their military spending plans and fight off the threat of further cuts to the defense budget.
The service chiefs, appearing before a Senate subcommittee on military readiness, took turns asserting that the defense budget, down 25 percent since the Cold War ended in 1989, had been pared back as much as it could be.
"We are as little and as lean as we can be," said Adm. Jeremy Boorda, the chief of naval operations. "Can we do today's missions? The answer is yes. . . . But we are at the limits of our ability to take on new missions."
The chiefs warned of a "bow wave" of problems created by the financial necessity of spending on today's combat readiness rather than tomorrow's weapons systems.
Gen. Ronald Fogleman, the Air Force chief of staff, said his service "cannot reduce modernization further and still sustain a credible combat capability." He warned that the "house of cards will tumble" if planned military funding was delayed.
Gen. Carl Mundy Jr., the Marine Corps commandant, said: "We are at a level that I cannot, in good conscience, reduce the Marine Corps one additional Marine."
General Mundy described the Marines as "ready" but "shallow." He said he would need an extra 20,000 Marines for a "robust" force. His current budget was $800 million below what he termed "essential" levels and up to $2 billion below "robust" levels.
Had Congress not added $3 billion to the fiscal 1995 Pentagon budget to pay for recent overseas missions, such as those in Rwanda, Somalia and Haiti, the Marine Corps would have been forced by a shortage of cash to stop all promotions, starting May 1, said General Mundy.
"We are that shallow in our funding," he said.
The chiefs were given a sympathetic bipartisan hearing by lawmakers. "Too many people here look at the Cold War being over and think of the Defense Department as a cash cow," said former astronaut Sen. John Glenn of Ohio, the senior Democrat on the panel. "I think we have cut too far already."
Sen. John McCain of Arizona, the subcommittee chairman who is a pro-defense Republican and former prisoner of war in Vietnam, wants to add $60 billion to the Clinton administration's military spending plans over the next six years. He would freeze defense outlays at $272 billion a year, a total of $1.63 trillion through 2001, compared with the administration's proposed $1.57 trillion.
But since Mr. McCain would make no adjustment for inflation, real defense spending would gradually decline.
GOP Sen. Pete V. Domenici of New Mexico, the Budget Committee chairman, favors holding defense spending at the lower Clinton outlay levels.
On the House side, Rep. John R. Kasich of Ohio, the Budget Committee chairman, has come up with a figure of $270 billion a year, higher than Mr. Clinton's proposal but lower than Mr. McCain's.
"I would be surprised if they cut defense any more than Clinton," said Carol Lessure, who handles congressional liaison for the Defense Budget Project, a Washington research group. "And I would be surprised if they increased it significantly."
Mr. McCain said the cash-strapped service chiefs were faced either with breaking faith with today's troops by shortchanging near-term military readiness or putting future national security at risk by delaying modernization of weapons systems.
In line with the general tone of that testimony, Gen. Gordon Sullivan, the Army chief of staff, told the panel: "I don't see the downward spiral stopping. The missions are up 300 percent, and you are asking us to do more with less."
He said the Army projected that it would need $100 billion this year. It received $60 billion. Its spending on new weapons and equipment has dropped from $30 billion a year to $10 billion. It is buying no new tanks, but upgrading old ones.
"These are dramatic changes," said General Sullivan. "And I don't see that changing."
Across Capitol Hill, Defense Secretary William J. Perry told the House Budget Committee that concern over short-term readiness was a "false issue," and advised legislators to concentrate on determing whether current spending plans were sufficient to ensure long-term military readiness.