[British Foreign Secretary Johnson arrives for the Conference on Cyprus at the UN in Geneva]Foreign ministers of Britain, Greece and Turkey were to meet in Geneva on Thursday in an attempt to thrash out a security deal for a post-settlement reunited Cyprus. For the first time in decades, the three countries were to address a 1960 treaty which allows intervention in Cyprus, a pretext used by at least one of them to intervene in the island in the past. Cyprus was split in a Turkish invasion in 1974 following a brief coup engineered by the military then ruling Greece.