“No more Mr. Nice Guy,” Donald Trump declared while trying to persuade Iran to agree to peace terms favorable to the United States. But this style of public diplomacy adds to the confusion about the state of American-Iranian negotiations. One minute, Iran agrees to “open” the Strait of Hormuz; the next, the United States tries its hand at blockading the Strait.

This is a test of whether the United States desires peace. Certainly, it mirrors the negotiating style during the Vietnam War. Lyndon Johnson would float the idea of “unconditional discussions” while pursuing military goals that seemed more like “unconditional surrender.” Trump proposes to pursue policies that suggest opening up commerce in the Persian Gulf, then quickly threatens to bomb Iran into “the Stone Age.” This is a mixture of Richard Nixon’s threats to deal out savage, punishing blows and mirrors Curtis LeMay’s promise to bury Vietnam.

Perhaps the crux of the dispute is that Trump, like Nixon and Johnson, really desires total victory in the guise of a peace settlement. Obviously, he wants to avoid a ground war, but what happens if the Iranians continue to resist effectively? But the push-me, pull-you style of negotiating could not help but persuade Iranians that, despite all the tough talk, Trump is reluctant to go all the way when it comes to a ground campaign. LBJ stumbled into a land war in South Vietnam after “Operation Rolling Thunder” failed to deter North Vietnam’s infiltration in 1965. Trump wants peace without having to send troops. And what if he does not want to? This creates a dilemma, which suggests another stage of escalation is inevitable.

If he does not commit big units to Iran, Trump is facing what Nixon did in 1972 when the US tried to change the tenor of the Paris negotiations, utilizing air power alone. The problem was that Nixon changed his position weekly while Henry Kissinger tried to hammer out an agreement with the North Vietnamese. The rough rhetoric does not match the honied language that suggests that Trump is interested in putting the affair behind him, with the Stock Market rallying when peace is mentioned and falling when it appears that Iran is a problem that refuses to go away.

The American negotiators have another problem: they have no credibility. Steve Witkoff and Jared Kushner have no credibility and for good reason. When not accompanied by Vice President J.D. Vance, their sole presence has led to attempts to assassinate Iranian negotiators. Whatever their views, Iranian negotiators should not have to fear a gangland-style slaughter when they show up to talk.

Trump should avoid the self-defeating act of confusing American external diplomacy with that of another government. To declare that you are not eager for war while allowing different factions within the US government to alter proposals by the hour, in the end, the US may resume the air war. But as John Negroponte pointed out after the Christmas bombing in 1972, “We bombed the North Vietnamese into accepting our concessions.”

If Trump is not precise about what he wants, he could risk having diplomatic egg all over his face.