HAS THE WAR Powers Act been completely invalidated by the Supreme Court's recent decision overturning the legislative veto? Maybe not, but certainly the teeth have been removed from the legislation. And even those provisions that remain may be subject to constitutional challenge on other grounds.

The law was designed to curb the president's power to use American troops abroad. Although the Constitution gives Congress the right to declare war, it also makes the president commander-in-chief of the armed forces. Using this power, American presidents have sent troops to foreign countries to suppress piracy, for example, to pursue criminals across borders or to protect American lives and property, without asking for or receiving a declaration of war. But it was what many thought to be the abuse of this power in the Korean and Vietnam wars that spurred Congress to enact legislation designed to regain some control without having to use its own power to declare war or to cut off funds for such military action.

The War Powers Act was passed in 1973 over a presidential veto. It concedes to the chief executive the right to send troops into hostile situations abroad for a limited period of time. There are some conditions though: 1) He must, if possible in advance, consult with and notify Congress of his action. 2) If troops are not withdrawn within 60 days, Congress must pass legislation authorizing them to remain abroad. 3) If Congress disapproves the temporary military action, it could, by legislative veto, direct the president to disengage the troops. It is this third provision using a legislative veto to cancel an executive action that was clearly invalidated by the court this week. The question is whether the first two provisions remain and, if so, how they can be enforced.

Sens. Percy and Pell, senior members of the Senate Foreign Relations Committee, suggest that, because of a severability clause in the law, both provisions are still valid. A president, they say, must still notify Congress when he sends troops abroad, and those forces cannot stay overseas after 60 days unless authorized by statute to do so. The president may still contest even this restriction on his powers by invoking his constitutional right to command the armed forces. That question is entirely different from the legislative veto dispute that has now been settled by the Supreme Court.

You may well wonder why these basic constitutional conflicts have not already been settled by courts. One reason is that the War Powers Act has not really been tested. Some instances of presidential use of troops have been without prior consultation but for a short duration--the Mayaguez incident in 1975, the attempted rescue of the Iranian hostages in 1980, for instance. Others have been continuous, like the stationing of Marines in Lebanon for almost a year, but Congress has chosen not to invoke the act. The country is in a strange and rather uncomfortable situation: until Congress asserts itself and tries to exercise the limited powers remaining in the War Powers Act, the role of each of the two branches in sending Americans into conflict will remain unclear.