Although Ankara has promised to sign the EU customs protocol by July, it has been holding back because of concerns that signing with Cyprus would equate to recognition of the Greek Cypriot state. Despite Turkish denials to the contrary, most observers agree it would. And because the Republic of Cyprus insists it has sovereignty over the whole island, it would imply Turkish non-recognition of northern Cyprus, or the Turkish Republic of Northern Cyprus, leaving the government open to criticism by nationalists that it was "sacrificing the Turkish Cypriots".
Checkmate!