Teachers and youth groups have been at the forefront of campaigns to reunite Cyprus peacefully - and last April the checkpoints opened, beckoning a flood of cross-border reconciliations among Greek-Cypriot and Turkish-Cypriot villagers who used to live together peacefully.

Cyprus has been split in two since 1974, when Turkish troops occupied the northern third of the island. Their action followed a coup staged by the Greek military junta in Athens against the Cypriot president, Archbishop Makarios, who had to be rescued by an RAF helicopter. The Turkish-Cypriots feared a repeat of attacks made against their communities during fighting in the 1960s. But the invasion forced 200,000 Greek-Cypriots out of their homes and tens of thousands of Turkish-Cypriots fled north.

It was the height of the Cold War and British bases on the island were being used to monitor Soviet nuclear missile tests in Central Asia. There is evidence to suggest the division was supported by the US to pacify Turkey and give NATO a foothold on the island as insurance against an expected British withdrawal from its logistical and intelligence facilities.

Ultimately, Britain stayed and the bases have since been used to help fight Osama Bin Laden and Saddam Hussein. But the Cyprus problem remains and is the greatest test yet of the EU’s ability to solve disputes between states.

Success would considerably enhance the prospect of Turkey joining the EU.

With NATO’s second-biggest army on board, the EU would then be far better equipped to develop rapid-reaction forces and a long-term military role.

As this supplement went to press, separate referendums in the Turkish-Cypriot north and more populous Greek-Cypriot south on a United Nations-brokered political settlement looked set to block acceptance. This would create an effective EUborder along an internationally unrecognised dividing line.

But the EU’s leverage over Turkey could be the key to ironing out the remaining differences. The Turkish government has agreed to a slow pull-out of its troops from Cyprus once a settlement has been reached on the island, because it is desperate to be given a date for talks on accession to the EU.

It is an example of how the EU has played its strongest card: changing the world without the use of force by demanding that countries meet its standards on democracy and economic transparency before they join.

Ironically, if a Cyprus settlement aids the development of a wider defence role, the EU could revert to using a more traditional form of political power: diplomacy backed up by military muscle.

Whatever happens, one curiosity will remain: the Sovereign Base Areas in Cyprus will stay British, but they won’t be part of the EU.