Pierre Elliot Trudeau, who on Saturday became Canada's fifteenth Prime Minister, is an unconventional man. He drives fast cars and wears sandals into the House of Commons. He has thrown snowballs at Stalin's statue in Red Square, and has been blacklisted by the U.S. State Department for suspected Communist affiliations. As a Montreal professor and journalist, he has spent a good part of the last few years criticizing and ridiculing the same Liberal party which this month chose him as its new leader. And as he assume Canada's highest office, Trudeau's political career is still only two-and-a-half years old.

The 48-year old bachelor's sudden rise to power comes while he is still almost entirely unknown both to the Canadian people and to the incumbent Liberal Party which elected him. What is certain is that he has youthfulness and charisma, and it appears that these were the qualities that the Liberals were looking for when they met in Ottawa three weeks ago to choose a successor to 70-year old Lester B. Pearson, who had announced his retirement last winter.

In addition to his personal appeal, Trudeau has had other factors working for him in his leadership campaign--his French Canadian birth, and an endorsement by Pearson's conservative Finance Minister, Mitchell Sharp. Many Liberals felt that a French Canadian Prime Minister would be best able to deal with French Canada's increasing demands for political and economic sovereignty. The problem with Trudeau was that he had a reputation as a leftist, and here Sharp's support served to convince many right-of-center Liberals that Trudeau was politically "sound" after all.

In fact, Trudeau's administration will probably be somewhat more "sound" than many of his supporters were hoping when they elected him. The new P.M.'s foreign policy (with Mitchell Sharp as External Affairs Minister) will probably not differ radically from Pearson's, although Trudeau has announced that he will seek to decrease Canada's military commitments to NATO and the United Nations. No break with the United States over Vietnam is forseeable, although there is considerable opposition to U.S. policies both in Canada generally and within the Liberal government. Trudeau has already made it clear that he will not attempt to interfere with the manufacture of Vietnam-bound war materials within Canada, as Canadian anti-war groups have demanded. While announcing plans to pull Canadian troops out of NATO, Trudeau has stressed the importance of continental defense arrangements such as NORAD, and it is fairly certain that Canada will be making no strong attempt to establish neutrality in the Cold War.

But the Trudeau administrations most severe test will come not on foreign policy, but over the question of the status of French Canada within the Canadian Confederation. Trudeau has taken a hard-line stance on demands by French Canadian nationalists--notably Quebec's Premier Daniel Johnson--that Canada's constitution be rewritten to confer a special status on Quebec transferring Quebec a wide range of powers now held by the Federal government in Ottawa. By opposing all such demands, Trudeau runs the risk of losing much of his remaining support among French Canadians--an ironic predicament for a French Canadian Prime Minister.

In defending the constitutional status quo, though, Trudeau best reveals the modernity of his thinking. He sees nationalism in French Canada as having replaced the Church as the force of social counter-revolution. Several years ago he described the Quebec separatist movement as "the work of a powerless petit-bourgeois minority afraid to be left behind by the twentieth century revolution," and it is clear that he has now extended the analysis to include nationalists such as Mr. Johnson.

Thus Trudeau's approach to Ottawa-Quebec relations is likely to be less diplomatic and cautious than was Pearson's. For Trudeau will attempt to do something that Pearson could never do: he will try to replace the Premier of Quebec as the leader of French Canada. This effort may well lead to a direct confrontation between Premier Johnson and Prime Minister Trudeau on the question of special status for Quebec. And if such a confrontation occurs, it could prove to be the turning point--one way or the other--in the 200 year history of French-English division in Canada.

At the moment, the new Prime Minister's chief concerns are Charles De Gaulle and his own popularity. In the past few days, Canada narrowly avoided breaking diplomatic relations with France after Quebec was invited to a Paris conference of French-speaking education ministers; Ottawa saw the invitation as an attempt by deGaulle to confer national status on the provincial government in Quebec. A last-minute compromise may have saved the situation for now, but with the French President showing no signs of discontinuing his political support of Quebec nationalism, further De Gaulle-Trudeau clashes appear imminent.

Trudeau's other immediate problem is finding a way to exploit the extraordinary burst of nationwide support which followed his election as Liberal leader. Because this kind of enthusiasm is certain to wane as the new P.M. is forced to make unpopular decisions, Trudeau is expected to call a general election at the first opportunity, in hopes of improving on his government's minority position in the House of Commons. Such a move may pay politically, but the burden of an election campaign will certainly add to the already considerable problems facing Canada's unconventional man in his first difficult weeks of power.