Former president Nixon and his former top aides - including then Secretary of State Henry Kissinger - could be ordered to pay thousands of dollars in damages because of their approval of illegal wiretaps of U.S. citizens, the U.S. Appeals Court ruled here yesterday.

The 3-to-0 ruling by the appeals court panel generally affirms a lower court's earlier finding that the actions by Nixon and his aides were unconstitutional. But it said the trial judge should have awarded more than a nominal $1 in damages and should not have dropped Kissinger from the suit.

The ruling, which lawyers described as the broadest rejection yet of the traditional claim that presidents and their aides are immune from civil suits for actions while in office, clears the way for a possible full trial of Nixon and his aides in connection with the wiretaps.

The finding came in a series of three wiretap decisions that place strict limits on the authority of the president to invoke his national security powers. In his opinion for the unanimous three-judge panel, U.S. Circuit Court Chief Judge J. Skelly Wright wrote that these powers may be invoked "only in instances of immediate and grave peril to the nation."

The court ruled that President Nixon and his aides probably violated federal wiretapping laws as well as the Constitution when they authorized telephone wiretaps on 13 government officials and four newsmen in 1969 to trace alleged leaks of confidential information.

The major decision dealing with the issue came in a lawsuit brought by former National Security Council aide Morton Halperin, whose home telephone was tapped for 21 months under the program. U.S. District Judge John Lewis Smith Jr. led in Halperin's favor in the lower court, and assessed the nominal damages of $1 - which the appeals court said was too low - against Nixon, former Attorney General John Mitchell and former Nixon chief of staff H. R. (Bob) Haldeman.

The wiretapping program was the basis for one of the impeachment articles against President Nixon when the House Judiciary Committee found it was begun for "political purposes."

In other ways, the wiretap program and resulting litigation over it was a thread that ran through several of Nixon's Watergate problems. For example, it was disclosed during the trial of Pentagon Papers codefendant Daniel Ellsberg when the government told the court Ellsberg had been overheard on Halperin's telephone.

The Halperin suit itself became the vehicle for numerous disclosures of alleged abuses of the national security wiretap program, and engaged the former highest Nixon aides in a round of finger-pointing as to who would accept the responsibility for the taps.

One of the largest victories for Halperin's side in yesterday's ruling was the reinstatement of Kissinger as a defendant. The trial court judge had found Kissinger's role had been "inactive" and had dismissed the case against him; the appellate court said that was premature because Halperin's attorneys had strong evidence indicating Kissinger had a more active role in the wiretapping.

In the Halperin and other related opinions yesterday, the appeals court also:

Reinstated a suit brought by New York Times Washington correspondent Hedrick Smith, whose telephone also was tapped. The trial judge had said the 89-day Smith wiretap had followed the proper procedure under wiretap law even though it was a "national security" wiretap and was therefore reasonable, but the appellate court said the trial court should look again and not accept "bland assurances" that national security was involved.

Said former Attorney General Mitchell could be sued for damages by members of the Jewish Defense League whose telephones were tapped by the FBI in 1970-71.

Recognized the conflict between the government's need to act decisively to safeguard national security and individual rights that arise in surveillance situations.

Wright acknowledged the "reality of dangers from foreign or internal conflicts," but said the Constitution and the law had to be followed "even in troubled times" to prevent invasions of personal privacy.

" . . . [Whatever] special powers the executive may hold in national security situations must be limited to instances of immediate and grave peril to the nation," Wright said.

Wright noted that when the Congress passed new federal wiretapping laws in 1968, it specifically left open the question of the president's power in national security situations. But he said it seemed clear that the federal wiretapping laws applied to the president where there is some question about the validity of the national security claim.

The court said it is finally up to the lower court judge to determine if the Halperin surveillance was a legitimate national security surveillance, but said it saw "little evidence" of that claim.

The tap stayed in place long after Halperin left the government and became a political adviser to Sen. George S. McGovern in his 1972 presidential campaign. Halperin claims the tap amounted to political spying.

The money damages provision of the wiretap law - $100 a day - could then be applied for every day of the 21-month period that the judge found the national security claim was invalid.

Wright said, however, under the constitution it was clear that a warrant was required when the tap was placed on Halperin's telephone in May 1969. Under both the Constitution and the law, Halperin could be liable for a substantial monetary award.

The court pointed out in all three cases yesterday that Nixon and his aides still could raise as a defense later that they acted in "good faith" on their understanding that the taps were legal at the time they were placed. That defense, however, does not block them from having to go to trial on lawsuits that accuse them of illegality.

"The president is the elected chief executive of our government, not an omniscient leader cloaked in mystical powers," Wright said.

U.S. Circuit Court Judge Spottswood Robinson III and U.S. District Judge Gerhard A. Gesell agreed with Wright in the three opinions.

However, Gesell wrote a separate opinion in the Halperin case expressing his concern about the possible "destruction" of the presidential immunity defense altogether by the court's ruling that Nixon and his aides are liable for damages.

He said a plaintiff in a lawsuit should be forced to prove by a preponderance of the evidence that a government official acted in bad faith before the official should be forced to trial. He said the court's ruling, and other opinions concerning the immunity issue, make private citizens think twice about assuming public office if their governmental acts are open to lawsuits.

Halperin, now director of the private Center for National Security Studies, said yesterday that the ruling was "a vindication of what I have been after."