IF EUROPE'S most deadly enemy had been allowed to choose the moment of the European Union's biggest institutional crisis in 42 years, he could have done no better than this one.

Monday night's resignation en masse of the European Commission has decapitated the EU's central institution in the run-up to long-overdue decisions on regional and agricultural policies, and financial and institutional reform - all of them preconditions to the planned enlargement to the east.

It comes, moreover, midway through a German presidency that is still reeling from the departure of the country's finance minister, and which has not covered itself with glory in the management of EU affairs thus far. "Europe is not without leadership," Chancellor Gerhard Schroder asserted yesterday. Others might beg to differ.

Leaders of the 15 EU member countries cannot win. The choice lies between allowing a caretaker Commission shorn of credibility to stay in office or devoting precious time and energy to the task of nominating a new one. A further complication will be the June elections for the European Parliament. Assuming that the new assembly insists on its right to approve a new executive, nothing may be settled for three months at least.

But business will not wait. The United States will not declare a moratorium in its double-barrelled trade assault on the EU, against the banana import regime and the common agricultural policy. The financial markets will not give the euro, which has dropped 8 per cent since its January launch, the benefit of the doubt until the Commission's house is in order.

Most important of all is Agenda 2000, reordering the farm and regional spending that accounts for the overwhelming bulk of the EU's annual budget and streamlining institutions which barely function now and would collapse entirely under the weight of a union of 20, 21, or even 26.

EU leaders were due to cut the Gordian knot at their summit in Berlin next week. Distracted by the implosion in Brussels, they will now find the task even more difficult, and the whole business may slip into the second half of 1999, by which time the Euro-novice Finland will have assumed the presidency. All members accept that without a deal on Agenda 2000, enlargement will be impossible.

Small wonder that Sir Leon Brittan, the outgoing vice-president of the Commission and Britain's senior representative in Brusssels, yesterday described events as "a disaster", which had to be handled with "ruthless determination".

But ruthless determination has not been a hallmark lately of either the member states nor the Commission which runs Europe in their name.