Egypt and Italy are caught in the turbulent wake of the Achille Lauro affair. This is, in any long-range scheme of things, a matter for keen regret. As Americans move beyond their anger at seeing the two countries do less than they could have to apprehend the killers, a concern for their political health cannot fail to come to the fore.

As Egyptians see it, Cairo could have taken political cover and turned the ship away, as others did; but to save lives and do a service it took the ship in. Having gone that far, it became politically unthinkable to hand over Arab perpetrators to non-Arab prosecutors. President Mubarak has incurred substantial costs as well as gains for having stuck in his fashion with his predecessor's openings to the United States and Israel, despite the continuing impasse on the Palestinian issue, which is critical to him. He should not have dismissed President Reagan's explanatory letter and demanded an apology, which was almost guaranteed to produce Mr. Reagan's terse "never." Still, it is possible to think, as we do, that Mr. Reagan was right to intercept the Egyptian airliner, and to understand the measure of humiliation and increased vulnerability that it brought upon an already frustrated Arab friend.

Italy faces a severe governmental crisis, apparently the first since the war to spring from a foreign-policy issue -- an issue bearing directly on links with Italy's principal ally. Defense Minister Giovanni Spadolini took his Republican party out of Prime Minister Bettino Craxi's five-party coalition yesterday, complaining 1) that he had not been consulted in the release of the fifth man (he wasn't, for the evident reason that he was a known opponent of the pro-Arab tilt that produced the release) and 2) that in the release certain legal and political obligations to the United States were ignored (with good reason, we believe, the Reagan administration concurs with Mr. Spadolini on this point).

But again, it is possible to think, as we do, that Mr. Reagan was right to reach for the fifth man, and to appreciate that Mr. Craxi has been an exemplary ally, one especially admired by a conservative American administration for his stands on defense and (until this episode) terrorism.

The distressing fallout leads some to conclude that had the results been properly anticipated, the actions precipitating them might have been avoided. But the actions were not accidental: they reflected logical though not unchallengeable political choices. Egypt and Italy did what they felt they had to do. So did the United States. They are all adult governments, and now they must deal with the consequences. They should do this in knowing respect for the importance of their bonds.