Let’s start with a definition. What is Annexation?
“Annexation is the legal incorporation of some territory into another geo-political entity (either adjacent or non-contiguous). Usually, it is implied that the territory and population being annexed is the smaller, more peripheral, and weaker of the two merging entities. It can also imply a certain measure of coercion, expansionism or unilateralism on the part of the stronger of the merging entities. Because of this, more positive terms like political union or reunification are sometimes preferred.
Annexation differs from cession and amalgamation, because unlike cession where territory is given or sold through treaty, or amalgamation where both sides are asked if they agree with the merge, annexation is a unilateral act where territory is seized and held by one state and made legitimate by the recognition of the international community”
http://en.wikipedia.org/wiki/Annexation
And what does international law have to say about the annexation of another state's territory?
Convention (IV) relative to the Protection of Civilian Persons in Time of War. Geneva, 12 August 1949.
Part III : Status and treatment of protected persons #Section III : Occupied territories
ARTICLE 47 - INVIOLABILITY OF RIGHTS
4. ' Annexation '
”As was emphasized in the commentary on Article 4 , the occupation of territory in wartime is essentially a temporary, de facto situation, which deprives the occupied Power of neither its statehood nor its sovereignty; it merely interferes with its power to exercise its rights. That is what distinguishes occupation from annexation, whereby the Occupying Power acquires all or part of the occupied territory and incorporates it in its own territory (4).
Consequently occupation as a result of war, while representing actual possession to all appearances, cannot imply any right whatsoever to dispose of territory. As long as hostilities continue the Occupying Power cannot therefore annex the occupied territory, even if it occupies the whole of the territory concerned. A decision on that point can only be reached in the peace treaty. That is a universally recognized rule which is endorsed by jurists and confirmed by numerous rulings of international and national courts.”
http://www.icrc.org/ihl.nsf/1a13044f3bb ... enDocument
So, is annexation of another state’s territory possible at all? Well apparently it IS but only under the following circumstances…
3. ' Agreement concluded between the authorities of the occupied territory and the Occupying Power '
"Agreements concluded with the authorities of the occupied territory represent a more subtle means by which the Occupying Power may try to free itself from the obligations incumbent on it under occupation law; the possibility of concluding such agreements is therefore strictly limited by Article 7, paragraph 1"
http://www.icrc.org/ihl.nsf/1a13044f3bb ... enDocument
Conclusion:
The Republic of Cyprus’ territorial sovereignty is protected by the UN Charter and specifically under the Fourth Geneva Convention of 1949, making it impossible for Turkey or any other country, to annex any territorial portion of Cyprus without the Republic’s consent.
Regards, GR.