Senate Majority Leader Robert J. Dole (R-Kan.) joined yesterday in introducing legislation that would give the president vastly expanded powers to respond to terrorist attacks, including possible au- thority to order assassinations in some cases.

The measure, cosponsored by Dole, Sen. Jeremiah Denton (R-Ala.) and House GOP conservatives Joe L. Barton (Tex.), Duncan L. Hunter (Calif.) and Robert L. Livingston (La.), would exempt counterterrorist actions from constraints on presidential authority that were imposed by the Vietnam-era War Powers Resolution.

In responding to terrorist attacks, the president would no longer be required to consult with Congress before sending U.S. troops into hostile situations.

This proposal runs counter to earlier pressure from other congressional leaders, including Senate Foreign Relations Committee Chairman Richard G. Lugar (R-Ind.), House Foreign Affairs Committee Chairman Dante B. Fascell (D-Fla.), House Minority Leader Robert H. Michel (R-Ill.) and Senate Minority Leader Robert C. Byrd (D-W.Va.), for improved procedures for advance consultations with congressional leaders. However, Michel said yesterday that he saw no problem with Dole's propos- al.

The legislation would authorize both preemptive and punitive strikes in response to terrorist threats from abroad, aimed at those who plan or support such acts as well as those who carry them out. It characterizes terrorism as as "an act of aggression against the United States" and says it "may be pursued with deadly force."

In addition to dropping consultation provisions for incidents involving terrorism, the bill would exempt counterterrorist responses from requirements for congressional approval for involvement of U.S. troops in hostilities lasting more than 90 days. It also would require presidential notifica- tion of Congress within 10 days of an antiterrorist action; currently, notification of U.S. troop involvement is required within 48 hours.

At a news conference to announce introduction of the measure in both houses, Denton said it "brings up interesting questions regarding other rules we have against assassinations."

Denton added, "I interpret the bill to mean that, as might have been the case with Libyan leader Muammar Qaddafi, had he become deceased as a result of our counterstrike, that would have been within the intent of this bill."

Dole did not address this point at the news conference, but Walt Riker, an aide to the majority leader, said later that "a case could be made for assassination but it would have to meet the qualifications of the law." Riker defined these as including instances of terrorism against Americans overseas and "solid evidence" linking the possible assassination target to the terrorist acts.

Asked if Qaddafi meets these criteria, Riker said, "The president would have to make that determination."

The lawmakers did not claim White House support for the measure, and presidential spokesman Larry Speakes said that, while the administration has reservations about the war powers act, it generally has not pushed for modifications.

Dole has been courting conservative support in laying the groundwork for a possible presidential bid in 1988, and some congressional sources attributed his sponsorship of the antiterrorist measure to that effort. In other areas, such as the budget, he has been a strong advocate of consultations between the White House and Congress.

Drawing a distinction between terrorism and other crises, Dole said that "there are times when the president must act and act quickly, and there won't be time for consultations." He said the War Powers Resolution, enacted in 1973 over President Nixon's veto, was passed with Vietnam in mind, not international terrorism, and should be adjusted to meet changed circumstances.

Lugar, whose committee will consider the legislation, said he saw no reason to change the war powers act, including its consultation requirements, which he said he wants to see strengthened through in- formal agreements between the administration and Congress. Opening the law to change could invite efforts to weaken as well as strengthen the president's powers, he cautioned.