When Leo Tindemans arrives in Washington Tuesday to meet with President Carter, he will be wearing two hats. The first Belgian Prime Minister to visit a U.S. President in 40 years, Tindemans also comes as acting head of the European Economic Community.

Recorgnized by other European leaders as a profound expert in foreign affairs, Tindemans intends to raise several points of discorn in his talks with Carter. His mandate as EEC statesman derives from Belgium's current role in the Common Market presidency, a post which rotates among the nine member countries every six months.

"Three points of friction with the United States worry Europe - the growing energy crisis, the low value of the dollar, and the rising threat of protectionism." Tindemans said, in a private interview here.

"Economics are involved with politics, and the prolonged world economic crisis is threatening stable U.S.-European relations," he warned.

Echoing the views of his European colleagues. Tindemans believes that the Carter administration has invested new faith in the Kennedy-era notion of an Atlantic partnership - that it is in America's interest to support a strong European community.

"Vice President Mondale's visit here in January set the new tone, and the December stop in Brussels by President Carter will further show that this administration wants to work closely with its European allies," remarked Tindemans.

The cooperative gestures taken by Carter's team contrast markedly with previous U.S. attitudes. "Unfortunately, Dr. Kissinger felt that Europe would always try to "gang up" on the United States," mused the 55-year-old Belgian leader. "That idea, of course was helped along by excessive French distrust of him at the time."

A zealous believer in European unity, Tindemans was assigned the task two years ago in EEC heads of government of drawing up a wideranging report on the future of Europe. But his clarion call for rapid steps toward economic and monetary union, as a way of fostering political integration, went unheeded.

"Most of the ideas in my report were expressed by my colleagues when I visited their capitals," Tindemans said. "But when I said it was time for action and not just words, everybody drew back from the fear of losing national sovereignth."

"There is no other solution for Europe, if it wants to regain its world influence, than to integrate," he added. "If we don't move forwards, the vision of a united Europe will be lost of good."

As the world's leading commercial power, the Common blarket must take the lead in seeking a peaceful solution to trade disputes with the United States and Japan, Tindemans feels.

The steel crisis in the western world has grown especially acute since so many jobs are at stake in U.S.-European trade "both sides may be guilty," says Tindemans. "European steel exports have hurt U.S. firms, but American steel shipped to Europe is also posing problems."

Japan also must realize that its mounting trade surpluses with Europe and the United States should be rectified if a liberal trading order is to continue, he added.

The rising U.S. dependence on imported oil and the low rate of the dollar also worry the European allies, he said.

The United States consumes twice as much oil per capita as EEC countries and must take conservation measures "or else the entire free world will suffer," he added.

The plunging dollar has hindered European efforts to improve trade balances and there is "much unhappiness" in EEC countries about the U.S. Treasury's reluctance to support the dollar on world markets, Tindemans noted.

Turning to EEC plans to add the membership of Greece, Spain and Portugal in the next few years. Tindemans shunned the argument that the Common market was intended to be "a rich man's club" and emphasizel the political necessity of bringing the nascent democracies into the EEC fold.

"We must also use that occasion to change the EEC way of taking decisions, which now requires unanimity, or else a 12-nation community will drift back to being just a simple trading zone," he asserted.

A man of protean tastes who speaks four languages fluently and has published seven books, Tindemans has taken an active interest in U.S.-European ties ever since he attended one of Henry Kissinger' Harvard summer seminars in international affairs 13 year ago.

He became Prime Minister in 1974, "in spite of my long term ambition to be foreign minister," he says. "But I plan to teach international relations when I retire. There must be some truth in the maxim - 'If you can't do it, teach it,'" he laughed.