President Clinton's economic embargo of Iran, announced Sunday, won't have much impact on that country. By all indications, the United States will stand alone in the boycott, and it was not one of Iran's key trading partners to begin with.

The only people sure to suffer monetarily are those who work for U.S. companies that do business with Iran. They had been exporting about $326 million to that country and were involved in the resale of up to $4 billion in Iranian oil each year.Yet, despite all this, Clinton was correct in calling an embargo.

Iran, long recognized by the State Department as a nation that harbors, supports and exports terrorism, is on the verge of becoming a nuclear power. For the past decade, Iran has organized and mobilized in search of plutonium and highly enriched uranium, the main ingredients for a nuclear bomb. After repeated failures trying to produce these items on its own, it has turned to Russia and China for help.

Unfortunately, Russia has been too willing to comply, agreeing to train Iranian nuclear technicians and to sell to them the nuclear reactors and gas centrifuge equipment needed to produce weapons.

If the United States doesn't stand up and protest this development, apparently nobody will. The results could be disastrous.

Even if the embargo is mainly symbolic, it will stand as an important statement against a nation that could begin exporting terrorism on a grander, more horrific scale. State Department officials already have linked Iranian-backed terrorists to tragedies throughout much of the Middle East, Africa, Latin America, Asia and Europe.

For the United States, however, the important step is yet to come. Clinton must be firm and resolute when he meets with Russian President Boris Yeltsin in Russia next week. Russia, if it wants to be a player in the community of free and democratic states, must back away from its support of Iran's nuclear program.

Then, the president needs to muster the diplomatic skills to persuade other allies, particularly the Group of Seven most industrialized nations, to join in applying pressure.

That may be a tall order, given the fact Clinton has shown little aptitude for foreign policy matters. But his announcement of an embargo is a good sign he may be maturing, and Congress appears ready for even broader get-tough measures. Some Republicans are calling for sanctions against foreign companies that do business with Iran.

Critics charge the embargo will escalate anti-American sentiments in Iran, perhaps even leading to an increase in terrorism. They note that Clinton and former U.S. presidents have steadfastly refused to link trade with atrocities in China, under a policy that maintains those problems are best dealt with separately.

Iran, however, is a much greater threat to world security than is China, and its history of anti-American rhetoric and attacks is too recent to ignore. To overlook a nuclear escalation in the name of exports and profits would be shortsighted. The world may end up paying a much bigger price at the hands of Iranians some day.

That is the message Clinton must carry persuasively to other nations.