The EU's decision to go ahead with Cyprus's membership application could destabilise the entire region. In order to understand the danger, it is necessary to recall a little of the island's recent history. When British rule ended in 1960, the new constitution vested sovereignty jointly in the two communities. It provided for a Greek Cypriot president and a Turkish Cypriot vice-president, both with veto powers. Cyprus was forbidden to unite with any other state, and the 1960 accords were guaranteed by Greece, Turkey and the United Kingdom.

Many Greek Cypriots regarded the settlement as biased against them, and, in 1963, they drove the Turks out of their positions in government. In 1974, supporters of enosis-union with Greece- staged a coup. As intercommunal violence flared, Turkish Cypriots called on the guarantor powers to intervene. When Britain did nothing, Turkey seized the northern third of the island.

The international community recognises the Greek Cypriot administration as the government of the whole island, acknowledging the 1960 accords. Yet those accords forbid Cyprus "to participate, in whole or in part, in any political or economic union with any state whatsoever". So EU membership is prohibited by the very constitution President Clerides cites as the source of his government's claim to the whole island.

This is no narrow legal point. By accepting their unilateral application, the EU has taken away from Greek Cypriots any incentive to reach an accommodation with the north. At the beginning of the 1990's, the outlines of a deal began to emerge: "Turkish Cypriots would relinquish some territory in return for recognition as equal partners in a bi-zonal federation. Once the Greek Cypriots realised they could treat with the EU on their own, however, they lost interest in the talks.

Membership is viewed by the Greeks as an opportunity to reverse the balance of power in the Levant by engineering a situation where Turkey is occupying EU territory; Turks see admission as enosis by another name. Brussels has been bullied into accepting this problem by Greece's threat to veto any enlargement of the EU. Turkey, which withdrew its threat to veto Nato expansion, is being punished for its responsibility, while Greece is rewarded for its intransigence.

Britain has a special duty towards Cyprus as a guarantor power. The Government must insist that an internal settlement be in place before the application is accepted. This is not just a question of dealing fairly with the two communities, or acknowledging that Turkey has been shabbily treated by Brussels, or even sticking to the law. It is a question of preserving peace in the eastern Mediterranean.