With little ado, the House of Representatives has declared that sending American soldiers into Grenada triggers the War Powers Resolution, which was passed in 1973 to give the nation's Legislature more control over warmaking.
While few lawmakers criticize the apparently successful assault on the tiny Caribbean island, they are attempting to salvage some congressional authority. They are telling President Reagan to remove the troops from Grenada by 60 to 90 days from the landing Oct. 25, unless he wins permission from Congress for a longer stay.
The House voted overwhelmingly Tuesday (403 to 23) to invoke the time limit. The Senate still must act, but it already agreed in principle when it approved identical war powers language last week in an amendment to the now-stalled bill to raise the federal debt limit.
If approved, the action would be the first time that Congress has tested the deadlines in the war powers law, which was written in the waning days of the Vietnam war amid hopes of avoiding future protracted military campaigns. Only a month ago Congress avoided a confrontation over who controls troops by voting to allow President Reagan to deploy marines in the peacekeeping force of Lebanon for at least 18 months.
But the invasion of Grenada is so obviously a case of the United States making war in a foreign land that even the Republican leaders in Congress support starting the 60-day time clock. Rep. William S. Broomfield of Michigan, the top Republican on the House Foreign Affairs Committee, told his colleagues this week that ''it is clear to me that the war powers act applies in this situation.''
No president yet has conceded the constitutionality of the war powers law's limitations on his power as commander in chief. In keeping with that tradition, President Reagan avoided mention of deadlines when he sent a brief report to Congress last week notifying it of the Granada invasion.
Reagan administration officials told congressional leaders just after the invasion that the troops could finish their work in a matter of days. But if armed forces are still in Grenada after Christmas, the stage could be set for a constitutional face-off between Congress and the White House.
If so, it would be the first evidence of a growl from a law that until now has been a toothless lion. A Congressional Research Service study has found at least seven cases of presidents dispatching armed forces without filing a report under the War Powers act. Among them is the use of military advisers now in El Salvador, the use of troops in Lebanon in 1974 and 1976, and the mobilization of troops in South Korea after violence in 1976.
Under the law, the president is required to consult with Congress before sending troops into areas of hostility. But no president has ceded to Congress the right to order troops home or set time limits on deployment.
Ironically, during the debate over passage of the War Powers Resolution in 1973, Sen. Thomas F. Eagleton (D) of Missouri argued that the act would actually strengthen the president's power to make war single-handedly.
''The bill gives the president of the United States unilateral authority to commit American troops anywhere in the world, under any conditions he decides, for 60 to 90 days,'' Senator Eagleton said then. Recently he has favored invoking the act he once opposed because ''it's better to have it than nothing.''