Since Vietnam, some Americans have been telling this diet-conscious nation that the United States has more political and military weight than is good for it or the world, and that it should shed some lest it be tempted to throw its weight around. But last week was a time for second thoughts about national weight loss. Weight can come in handy.

Some people supposedly sensitive to Arab sensibilities portray Arabs as crazed. They say Qaddafi's status will be enhanced in the Arab world. That assumes Arabs cannot recognize a fiasco. Besides, "the Arab world" is a geographical, not a political, expression. That world is riven by mutual detestations more powerful than sympathy for the "martyrdom" of Qaddafi, which consists in his getting his young men killed pointlessly.

The Libyan regime, like the Cuba and Nicaraguan regimes, derives its dynamism from the charisma of a dictator who depends on bravado, which depends in turn on U.S. hesitancy. Such episodes as last week's in the Gulf of Sidra usefully demonstrate that such leaders swagger at our sufferance, which has limits.

What is limitless is the faith of some Americans in the power of talk to tame aggressors. Rep. Michael Barnes (D-Md.) is a conscientious communicant in the Church of Negotiations. Last week the planes were barely back on their carriers before Barnes declared they should not have taken off: "There are probably ways that we could have worked with other nations to establish the principles of freedom of the seas and access to international waters without endangering our military forces and without any loss of life." Such multilateralism is isolationism that dares not speak its name. And the suggestion that U.S. force was used unnecessarily is a form of blaming America first.

Sen. Chris Dodd (D-Conn.), asked about the president's decision to respond to the Sandinista incursion into Honduras by sending $20 million to Honduras, said: The Sandinista attack demonstrates the folly of the policy of aiding the contras.

Now. There is a logic-chopping point here: If there were no contras, there would be no contra bases for the Sandinistas to attack. But even if there were no contras based across the border, there would still be that border, and the Sandinistas dare to speak their attitude toward borders.

On Jan. 30, l942, in Berlin's Sportpalast, Hitler vowed "the complete annihilation of the Jews." Learned diplomats wondered: "What is he trying to say?" Trying? He was saying it, and not for the first time. Allied governments went on insisting there was "no substantial evidence" of genocide. When will the democracies learn that the reiterated vows of totalitarians is substantial evidence of intentions? When the Sandinistas say they are conducting a "revolution without borders," they are saying -- "trying" to say? -- that they so despise U.S. resolve they do not bother to disguise their intention to run roughshod over their neighbors.

With the essentially party-line vote in the House against contra aid, the Democratic Party is again driving lickety-split into the cul de sac it found itself in two years ago in the New York primary. Then, Hart and Mondale competed to see who could pledge to withdraw U.S. forces from, or keep U.S. forces out of, more places. Hart won that contest by a whisker because Mondale said he would permit two-dozen U.S. advisers in Honduras.

When the House decided by just 12 votes against contra aid, some votes probably were lost because Pat Buchanan of the White House wrote a column for The Washington Post. He said the vote required representatives to side with the president or Nicaragua's dictator, Ortega. This infelicity occasioned much outcry about "McCarthyism" and "questioning of patriotism." Men are dying, and decisions about their fate are being influenced by pique about a newspaper column.

On the "CBS Morning News" March 26, Phil Jones, CBS's respected Capitol Hill correspondent, was asked about the Sandinista incursion. Jones said: "He (Ortega) has done something that certainly has hurt his case in the U.S. Congress." Imagine the uproar that would result were Buchanan to say that Congress has been voting for or against "Ortega's case."

Jones was talking reasonably, naturally. We should listen to the resonance of such natural discourse. Extreme delicacy is required when speaking of the contra-aid vote, lest persons voting against aid feel slandered by the suggestion that they supported Ortega's "case in Congress." When natural discourse about a particular vote, such as the vote against contra aid, causes those who voted that way to wince, they should wonder whether they voted wisely.