LONDON  Ireland’s vote to ratify the European Union’s Lisbon Treaty has finally cleared the way for the creation of a powerful new president, intended to elevate the 27-nation bloc’s standing on the global stage.

But do European leaders actually want one?

Ahead lies a difficult discussion about how much power and influence a new European Union president should have and whether the post should fall to a political star  like former Prime Minister Tony Blair of Britain  or one of his grayer, more technocratic rivals.

The leaders of member countries will decide, probably this month, and their decision could determine whether the union really seeks the bigger role it says it needs to try to match the influence of the United States and that of rising powers like China, Russia, India and Brazil.

The Lisbon Treaty, which aims to streamline decision-making and reform the bloc’s ramshackle structures, lays down a two-and-a-half-year term for a full-time president of the European Council, the body that represents member nations. The treaty, if finally ratified by the Poles and Czechs, also mandates a single new foreign affairs chief, in charge of both policy and aid money, and a new European diplomatic corps.