The Post's swipe at President Carter's statements on Nicaragua {editorial, Nov. 24} was a predictable cheap shot at the man who shunned the Washington establishment so dear to your hearts.

When you state that Carter was "the one on whose watch the Sandinistas took power," it's clear The Post has been listening to too much Cold War rhetoric. Nicaragua is a foreign country. What was he supposed to do, send in the (U.S.) National Guard?

Considering the many years of Somoza's bloodletting -- aided by uninterrupted U.S. aid -- what happened in Nicaragua after its revolution was mild compared with, say, the Russian or French revolutions. Yet The Post calls the Sandinistas "spoilers" (of what?) and says neighboring El Salvador was a victim of "a Sandinista attack {Carter} had desperately hoped would not come." What attack?

If The Post really believes after seven years of U.S.-sponsored war in both Nicaragua and El Salvador that Ronald Reagan is doing more for peace than his predecessor, then you should seriously consider putting reporters in the small towns being devastated in each country -- with weapons paid for the U.S. taxpayer.

Mike Malloy

The fence-sitting Post editorial writers must have loved composing "Jimmy Carter and Nicaragua": a chance to take another shot at Carter and come down again on the contra issue. Vintage Post: we never have supported the administration's contra policy, but ''it takes a willful blindness not to grant that the contras, besides the bad they did, contributed to the pressure that led Managua to sign the peace plan.'' Every cloud has a silver lining. By the way, doesn't it also take a willful blindness not to grant that Jimmy Carter and Jim Wright, besides the bad they did, contributed to the pressure that may lead the administration to give the peace plan a chance?

And, by the way, the bad the contras did and do is terrorism, plain and simple.

Mark A. Venuti