Even before Reagan signed the treaty with Gorbachev on Dec. 8, right-wing strategists were organizing. One week before the signing, the core of ''the outside network'' -some two dozen conservative leaders heading mass organizations that claim a total of 1 million to 2 million members - held a strategy dinner at the Ramada Inn in suburban Tysons Corner, Va.

The table talk, recalled one participant, was full of frustration, and focused on the question of ''what to do about summit fever, what to do about Reagan's relationship with Gorbachev - the idea being that Reagan was appeasing liberals in Congress, appeasing the Communists, caving in on taxes, putting moderates like Frank Carlucci at Defense, and cutting deals with the evil empire.''

But Phillips's knock-out punch will be a full-page ad scheduled to run this month in such conservative-minded newspapers as The Washington Times and New Hampshire's Manchester Union-Leader. Under the headline, ''Appeasement is as unwise in 1988 as in 1938,'' photos of Reagan and Gorbachev are paired with photos of Neville Chamberlain and Hitler, followed by the appeal: ''Help Us Defeat the Reagan-Gorbachev INF Treaty.''