THE Achille Lauro affair is providing us with another example of how surprising and unexpected can be the consequences of the use of military force. The purpose of using American seaborne air power to obtain custody of the Palestinian hijackers of the cruise ship Achille Lauro was to discourage Palestinian nationalists from committing acts of violence, that is, ``terrorism,'' against their enemies.
The actual results have been to bring down the most stable government Italy has enjoyed since World War II and fuel anti-American emotions in Egypt to the danger point.
An incidental result has been to expose publicly and openly a rift in the alliance over Middle East policy.
The West European allies and Egypt are now dissociated visibly from America's pro-Israel positions and actions.
The action itself was efficient and a credit to the United States Navy and its fliers. President Reagan gets a public-relations plus at home. Americans like to have their military power used well and successfully. The use this time was successful in terms of the assignment. The fliers intercepted, guided, and brought down, without loss of life, the plane they were told to intercept and bring down, safely.
The military operation provided a pleasing contrast to the bungled attempt during the Carter administration to rescue the American hostages in Iran.
But a successful military operation and its political consequences are two different matters.
The general, underlying purpose was to support Israel. The operation did so in the sense that it exposed the US as using its military power against Israel's enemies. But this readiness of the US to use its military force in support of Israel is unlikely to discourage the Palestinian nationalists. They are bound to come up with some new operation in pursuit of their unresolved war with Israel.
One side result might be to increase the inclination of the Palestinian nationalists to identify Americans in general with Israelis, and thus could mean more American targets in their gun and bomb sights. American diplomatic and commercial people are probably in greater physical danger throughout the Arab world.
The increased American identification might also mean a reduced danger to the nationals of the countries that have dissociated themselves either openly, as in the case of Italy and Yugoslavia, or by implication, as in the case of West Germany, Britain, and France, which condemned the Israeli bombing of PLO headquarters in Tunisia and refrained from applauding the interception of the Egyptian airliner.
Italian Prime Minister Bettino Craxi may well recover from the affair and reform a working government. Italy will not leave the NATO alliance over the Achille Lauro affair. But its government will undoubtedly seek to be more independent of US leadership in foreign policy. Anti-American sentiment has long been dormant and scarcely detectable in Italian politics. It is again a factor.
Egypt is a more serious matter.
The Cairo street mob is anti-American for many reasons, including the rising influence of Islamic fundamentalism. In this case some of the worst anti-American riots were by university students. The pro-American policies which Prime Minister Hosni Mubarak inherited from his predecessor are under fire now both from the fundamentalists and from the young intellectuals.
Mr. Mubarak could gain in political strength and mass popularity by repudiating both the treaty with Israel and the American association. He will probably do his best to resist the pressure, and may succeed. But there is a new question mark over his political survival.
If he fell, the Israeli treaty and the American association would almost certainly go down with him.
As was said in the beginning, it is difficult sometimes to foresee all the consequences from the use of military power.