Europe’s politicians have cleared the last hurdle in accepting Greece’s third financial bailout but the voting was uncomfortable for everyone. The left-wing populist government in Greece relied on representatives from the more traditional centre-left and centre-right to cover for defections from the ruling coalition; the German government used Social Democrats within the ruling coalition to cover for defections from the Chancellors own Christian Democrats; and the Liberal (VVD)/Party of Labour (PvdA) government the Netherlands got extra support from the left-liberal D66 party to add to its slender one-seat majority.

As a result of these different movements toward the political centre – and similar developments in other countries – the Greek government will get the money it needs to keep up with its debt payments and shore up its banks. That is a good thing for anyone who wants to see Greece have a reasonable chance at recovering from this ongoing crisis. Unfortunately, that centre cannot hold. A populist party like Syriza cannot govern easily with the old pillars of the Greek political establishment; Germany’s grand coalition is an historical anomaly; and the result of eight years of close cooperation between VVD, PvdA and D66 was bad for all. So the question is whether Europe’s political centre will splinter before the Greek situation becomes sustainable.

It is easy to explain why Europe’s political centre cannot hold indefinitely. The people who identify with the political centre learned through experience that European voters have lost their patience with long-running broad-church movements. The once-hegemonic Christian Democratic parties that dominated political life in Belgium, Italy, and the Netherlands are faint whispers of their former selves. The social democrats have not fared much better. This is obviously true in those countries like Sweden where the social democrats were as hegemonic as the Christian Democrats were elsewhere (even if they may have proved to be more durable). But it is also true where there has been more consistent right-left alternation. Those social democratic parties that moved to the centre to try and consolidate their hold over the electorate, like Gerhard Schroeder’s SPD or Tony Blair’s Labour Party, inevitably found themselves challenged on the Left. Matteo Renzi’s Democratic Party is experiencing much the same, only faster.

These lessons have had a strong impact on behaviour both among politicians and among voters. As a consequence, centrist politicians do not enjoy working together. They may like each other personally and they may agree on many issues but they know that the key to getting re-elected is to convince voters to make a choice. For their part, the electorate expects these choices to be honoured. As a result, voters tend to regard centrist grand coalitions as a form of betrayal. Rather than rewarding politicians for setting aside their differences, they put a curse on all participating political parties when they return to the polls. Many a populist or anti-elite group has benefited from this process. Austria’s Freedom Party is one example; the French National Front is another; the Dutch List Pim Fortuyn is a third. These groups are similar only in terms of opportunity and not ideology. They arose at least in part because voters preferred choice over the alternative.

This necessity for choice is what puts Europe’s political centre on a short clock. You can see this in the manoeuvring around a possible confidence vote in Greece where the same opposition groups that supported Prime Minister Alexis Tsipras in pushing through the legislative preconditions for the third bailout are now threatening to withhold their confidence from the Syriza-led coalition. It is evident in the Netherlands in the sharp attacks levied by D66 leader Alexander Pechtold on VVD Prime Minister Mark Rutte for having promised the voters during the last elections never to give more money to Greece. And it shows up in the nervous counting of CDU/CSU defectors from Chancellor Angela Merkel’s leadership as pundits look ahead to Germany’s 2017 parliamentary elections. The fact that the increase over July was less than many observers expected offers only cold comfort: sooner rather than later Merkel’s SPD coalition partners will have to begin differentiating themselves from their Christian Democratic coalition partners and this will force Chancellor Merkel to shore up her position on the right. Against this backdrop, it is hard to see how Europe’s political centre can hold together throughout the three-year life-span of the third Greek bailout agreement. Indeed it may start fracturing in a matter of weeks or months.

The fact that Europe’s political centre cannot hold is no reason for Europeans to give up hope. On the contrary, it is a strong argument for the importance of European institutions: The European Commission, the European Central Bank, and the European Stability Mechanism were created precisely to sustain policy action across changes in member state governments. Politicians should offer voters a choice and the outcomes of those choices should be respected. But that is not the same as saying that every European policy should be held hostage to every change in member state government and neither should it mean that historic agreements like those reached over the past several weeks should be held hostage to the fates of an unending succession of national electoral contests.

The European Union exists because there are problems bigger than any member state government can address on its own. The EU also exists because there are issues that can only be tackled over time periods longer than the gaps between European parliamentary elections. Europe’s political centre cannot hold, but we have always known that. European integration is the response.

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