Britain, in World War Two, the worst global conflict there has ever been, did more for Europe than any other country. Many brave Irish men and women took part in that. Britain saved the rubble-filled charnel-house to which central Europe had been reduced from an unthinkable fate and then handed it over to what became the Treaty of Rome signatories to make it whole again.

The key foundation countries did make it whole again with great dedication and a 50-year success story that has since suffered strain, confusion and loss of direction, leading to a series of crises that are far from over.

The people of Ireland, who were isolationist during that great conflict to defeat Hitler, came late to the EEC along with Britain, committing ourselves to the huge advantages that flowed from the EEC and then the EU. We brought no power politics into the mix but received much help in our development.

Britain was entirely different, bringing sufficient strength to affect the balance of power in Europe and doing so with a tolerance and generosity towards its small neighbour, ourselves, that was not always reciprocated.

We were emotionally at odds. Successive British governments simply recognised the inextricable trade, business and financial involvement and made again what there had always been – a link that could not be broken.

In his speech of last week, David Cameron touched on all of this save the relationship with ourselves, which he takes on trust, knowing that most of our interests are common. And if we look at what he said, we will recognise the truth of this.

Above all, this is evident in the five principles that were at the heart of his speech. But it is also evident in the psychological definition of the British people as "an argumentative and rather strong-minded member of the family of European nations . . . independent, forthright, passionate in defence of our sovereignty". How like ourselves, one might say, but as we used to be, not now.

But then Mr Cameron goes on: "We come to the European Union with a frame of mind that is more practical than emotional. For us, the European Union is a means to an end – prosperity, stability, the anchor of freedom and democracy both within Europe and beyond her shores – not an end in itself."

And then he adds: "But all this doesn't make us somehow un-European."

He asks difficult but revealing questions, firstly about the eurozone that has brought about fundamental and negative change, dividing the 27 members into two quite distinct clubs, with Britain, a big European power, linked with non-euro countries and witnessing from the outside the unstable, crisis-torn eurozone.

His second and third observations about crisis in Europe are closer to ourselves, one of them being the crisis of competitiveness and the other the democratic accountability gap between the EU and its citizens.

We in this country have rather nervously knuckled under and surrendered much of our democracy and sovereignty. Despite ambitious words about reversing this, the reality sees this democratic deficit as a long-term situation.

Mr Cameron sees it differently, as both a pragmatic and political opportunity. By facing the challenge that is damaging to British trade and enterprise, he will strengthen the Conservative Party against Labour. He will also strengthen his own hand on the European question with die-hard opponents among members within his own party.

His critique of Europe is an important part of the shaping of his and his party's political future. He sees a great deal wrong with Europe at this time – surely we all agree with that – but central to his thinking is the log-jam of EU and eurozone inflexibility.

Hence his five principles, the first of which is competitiveness through the re-emphasis of the core value of Europe's single market. European bureaucrats and the two-tier system involving the eurozone and the others undermines the need for and the achievement of a new set of smoothly working market economies.

He spoke as leader of a country that has always been among the leading trader nations as well as a leader in the family of democratic nations, "all members of one European Union, whose essential foundation is the single market rather than the single currency". That binding principle within a more flexible and freer, more democratically legitimate Europe, is at the heart of the speech.

For this to work, power has to flow back to the member states. "We cannot harmonise everything," Mr Cameron said. That, he believes, would be a denial of democratic legitimacy.

Despite our less than whole-hearted membership of the euro and our subjugation by it, we would accept his principle of fairness between the EU's increasingly divided currency structures.

The political subtext of how he has tried to tackle a divided Tory Party, to outsmart the UKIP threat, upstage Labour and provide a political pathway through the years immediately ahead, has obscured the more fundamental truths about Europe's problems. In theory, there is no mechanism to meet his confrontation of the EU. The Treaty of Rome is a one-way journey.

Mr Cameron has therefore entered territory we never conceived of him entering. Nevertheless, his determination is to create the necessary mechanism for the kind of re-think he wants. It leaves open at this time the ultimate course he will follow.

Other countries, mainly the major EU powers, have previously achieved major change. Why not Britain? For those here who share belief in his five principles, he is therefore a strong ally.