WASHINGTON — Because of the expected resignation of Secretary of Defense Caspar W. Weinberger, the Reagan Administration is preparing a major shuffling of its most senior national security advisers as final plans are being made for the U.S.-Soviet summit conference next month.
In the short run, the anticipated departure of Weinberger is not expected to have a major policy impact. Citing his lack of involvement in the last meeting between Reagan and Soviet leader Mikhail S. Gorbachev in Iceland, for example, Administration officials predicted that the secretary's absence would have no impact on current summit preparations.
But hard-line conservatives expressed fears Tuesday that his likely replacement by National Security Adviser Frank C. Carlucci, widely known as a conciliator, may weaken the Pentagon in disputes over arms control policy with the State Department.
"I don't think Carlucci has the same relationship with the President that Weinberger has. That has been instrumental in the exercise of influence by Weinberger," a former senior Pentagon official said.
Some conservatives complained that former Sen. John Tower (R-Tex.) would be a better choice for the post because he has the President's confidence and is seen as a hard-liner on arms control issues.
Those critics believe that Carlucci's expected nomination was engineered by White House Chief of Staff Howard H. Baker Jr. and Secretary of State George P. Shultz--his allies among the so-called Administration "pragmatists" in their continuing dispute with the President's more conservative allies--to guarantee their authority over foreign policy.
The White House plans Thursday to announce Weinberger's resignation, the nomination of Carlucci and his replacement by his deputy, Army Lt. Gen. Colin L. Powell, sources said. Weinberger is resigning to help care for his ailing wife, Jane, and not because of any policy dispute, according to senior officials and friends of Weinberger outside government.
Although Mrs. Weinberger confirmed the resignation in an interview published today in The New York Times, she suggested her health was not the reason. Unidentified friends quoted in the story, however, said Mrs. Weinberger was trying to be stoic about her worsening condition.
Weinberger is expected to remain in his post, which he has held since the beginning of the Reagan Administration in 1981, until his successor is confirmed by the Senate--a process that could be delayed until after the summit meeting, which begins in Washington on Dec. 7.
Senate Minority Leader Bob Dole (R-Kan.) said after a White House meeting that he did not expect Carlucci, who has maintained good relations with Congress, to encounter any difficulties in receiving Senate approval.
'A Tenacious Man'
Although Carlucci was a protege of the defense secretary, Weinberger has a much more combative reputation. " 'Cap' is a very tenacious man," said a former senior Pentagon official, using Weinberger's nickname. "He fights until the battle is over and then he continues to fight."
Weinberger's hand was strengthened further by his close personal relationship with Reagan, an association that has lasted for more than 20 years as an adviser in and out of government. He has been a Reagan confidant since Reagan's days as governor of California and--along with Samuel R. Pierce Jr., secretary of the Department of Housing and Urban Development--is one of only two members of the original Reagan Cabinet still serving in their posts.
"Whether a lame duck will have the same influence as someone who is staying on is a good question," said Robert B. Sims, Weinberger's former spokesman. But, Sims added, Weinberger "is likely to be able to make his weight felt right up until the last because of his relationship with the President and his seniority in the Administration."
Carlucci 'More Wily'
Another former Pentagon official, pointing out the differences between Weinberger and his expected successor, said that "Carlucci is in many ways more wily." However, he added: "I just don't know about Carlucci's endurance."
Even more uncertain is the impact that Powell would have as Carlucci's replacement in the national security post. The career Army officer, one of only a few blacks at his level in the armed forces, is known as a general with finely tuned political senses who is unlikely to take on deeply entrenched forces in the civilian arena.
But, said one former senior Pentagon official who worked with Powell several years ago when the general was Weinberger's military assistant, "Colin Powell will strengthen" the National Security Council staff.
And, on Capitol Hill, Carlucci could be expected to improve the Pentagon's relations with Congress as defense secretary, although congressional sources and outside analysts said he may have limited effect inside the massive military bureaucracy.