THERE ARE at least two specific political lessons that can be drawn from the hostage crisis, one true and one false.The false one is that the United States has no future in the Third World. The evidence for this is that the hostages were seized not-withstanding the fact that Jimmy Carter had been moving systematically to accommodate the new regime. Indeed, his warming evidently struck some Iranians as a threat to their program for revolution. That's why, an unspontaneous 13 days after the shah arrived in New York, they struck.

Yet no simple Third World conclusion follows. Certainly the United States must be sure to give no overt comfort in any way now to a bandit regime. But a broad American interest in Iran's oil, stability and territorial integrity necessarily endures. There is also the example of Algeria, the indispensable mediator. In respect to Iran, the Carter premise of American-Third World commonality was sapped, but in respect to Algeria, recently under new leadership, it was strengthened. Clearly, it's a matter of dealing with these countries one by one.

The second specific lesson that can be drawn is true, and it is that power tells. By power we mean not simply counts to ships and planes, though these are important, but others' perceptions of American readiness to use them. Did it not catch the attention of those who seized the American diplomats that Mr. Carter had seemed to let an earlier seizure pass? Did his relative restraint in the Nov. 4 kidnapping strike the Kremlin as it puzzled over how to bring the Afghans into line? This is not to say that events do not have complex causations. But one factor in the mixture will always be a judgment of the American reaction, and this is a factor the United States is uniquely well placed to influence.

It did not take President Reagan's inaugural address to make clear that he understands this well. But he will have to navigate in complex circumstances. This time, he clearly helped to make the difference by flaunting his image of muscular unpredictability. The next time, domestic consensus and international support may not be so available. Military might can be expanded, but it cannot make American factories and cars run without oil.

Still, we are inclined to agree with Mr. Reagan that the essential element is, as he puts it, "will and moral courage." These qualities cannot be divorced from physical resources of various sorts. The will to use available power is, however, a critical first line of defense against further outbreaks of terrorism aimed at the United States, and against a whole range of more traditional threats.