The "situations vacant" created by the likely ratification of the Lisbon treaty have prompted an intriguing debate about the future direction of the newly energised European Union.

Eight years after the Lisbon reform treaty was first drafted, these are strange times for the EU. As the former Finnish prime minister Paavo Lipponen has pointed out, since the Single European Act of 1986, the community has been in a continuous state of institutional reform and treaty changes.

"For the first time in the history of the modern European Union there are no plans now for another round of intergovernmental negotiations for basic treaty changes." No wonder a cheer went up at the leaders' formal dinner when they were told the Czech Republic's president Vaklav Klaus had indicated he would be No 27 to sign on the dotted line, barring any (unlikely) constitutional problems.

And so the race to fill the two big jobs created by the treaty is on. The successful candidates for these fledgling posts of EU president, or chairman, and the position with a title straight out of a Gilbert and Sullivan operetta – EU High Representative for the Common and Security Policy – are being described as having a fundamental bearing on the future direction of the more integrated Europe that's likely to develop over the next few years.

But do the EU leaders want somebody (Tony Blair?) who "stops traffic", is recognised as a media superstar and would be the sort of person Barack Obama can call when he wants to talk to "Europe". Does the EU, as British foreign secretary David Miliband said, risk becoming irrelevant in a world in which the United States and China dominate, if they do not appoint somebody of global stature?

Or does the EU want a president who is more of a chairman of meetings than a chief, somebody who is an internal fixer and a facilitator among the 27 leaders, who will act as a steadying channel through which consensus can be attained?

These two roles have been presented largely as an either/or, mainly because the British media has gone into hyper-drive over the possibility of Tony Blair getting, and then not getting, the job. But there is no reason why the new president can't provide both political vision and charismatic leadership on the world stage, as well as possess the necessary people skills to help 27 diverse nations discover where their joint interests lie.

One thing is certain: the top job won't go to a country that, to coin a phrase used so often in the Lisbon referendum campaign, is not "at the heart of Europe". That, ultimately, has been the downfall of the Blair campaign. Europe does not want its agenda set by a leading former politician from the country that is most sceptical about its ability to act as a unified zone of interest.

Significantly, Angela Merkel, the newly elected chancellor of Germany and most powerful leader in Europe, has let it be known she does not back Blair and has refused to be drawn about her preferences until the Lisbon treaty is finally ratified by the Czech president next week.

John Bruton's decision to put his name in the hat has added real spice to our interest in the changing structures of the union.

It might seem presumptuous of Bruton, who has been virtually invisible to the public at large in his role as the EU ambassador to the United States, to unilaterally declare himself a candidate without first consulting with Fine Gael and without telling Taoiseach Brian Cowen. His announcement caught the Taoiseach offguard and, having backed Tony Blair before the Bruton name emerged, Brian Cowen initially appeared lukewarm in his support for the Irish candidate. But Micheál Martin is unfailingly canny about the importance of optics in the European arena. By having an Irish contender, albeit a rank outsider, Ireland is once again signalling it is a European player – limping badly, but not a spectator.

The other big vacancy is that of foreign policy chief – arguably as important, if not more so, than the president. Both president and foreign policy chief will work together in building consensus among EU countries.

As the difficulties involved in getting agreement on climate change before the Copenhagen global climate change conference next month showed, the office – with its greater powers, budget and staff – was never more vital. Climate change is the issue where isolated national action is pointless.

The 27 leaders reached consensus of a sort in agreeing they will pay their "fair share" of the €50bn a year contribution by rich countries to the €100bn a year deemed necessary over the next decade to encourage developing countries to implement carbon reduction policies.

But the agreement fell short on the specifics and leadership environmental campaigners believe Europe should provide. How much better can Europe do when it develops both a visible and cohesive policy on not just climate change, but a whole range of issues from aid to developing nations to energy security and economic reform?

European politics was, is and always will be about complex compromises. European foreign policy was, is and always will be about negotiating a path among the various competing spheres of interest and special relationships among the 27 nations.

But over time there is no doubt, now the structures of Europe have finally been decided for the medium term at least, that Europe at last can start to build the identity all of its people want.