Well, when one of the Unholy Trinity of Guarantor Powers stages a coup, one invades and occupies for 40+ years and one, at the very least, does nothing, an inaction that promotes the interests of its various allies.
... and that's not including the hidden actions, the false flag ops, the gun-running, from 1960 onwards that did so much to contribute to the destabilisation of the Republic and promote sectarianism and eventually a near-partition.
There cannot have been a more discredited international agreement than the ToG.
Mehmet Levent writes in Afrika, replying to Erdogan's insistence that Turkey will maintain its Guarantor/Intervention/Inavade and Occupy at any time of its choosing "rights" ...
"... They are the ones who plotted the 21 December 1963!
Who organized the coup against the Republic of Cyprus? The fascist junta of guarantor Greece!
Who showed as an excuse this coup, interfered militarily in Cyprus and occupied half of the island? Guarantor Turkey!
Who distributed the property of the Greek Cypriots, whom he sent away, to the population he brought and settle from Turkey? Guarantor Turkey!
Who boasts of changing all the international balances without withdrawing a single soldier, without giving a handful of land? Guarantor Turkey!
Who does not recognize and ignores the Republic of Cyprus, which is recognized by the entire world? Guarantor Turkey!
And finally who remained only a spectator to all these disgraces, to these illegal fait accompli, who said nothing against the island’s being divided in two, like a watermelon, by Turkey with the use of force of weapons and with costing the lives of thousands of people and [who said nothing] to the establishment of an illegal state dependent on Turkey and therefore who became an accomplice to the war and the crime against humanity that caused bloodshed on the island? Guarantor Britain! […] ..."
"... In case a just solution acceptable by both sides is reached, Cyprus will not need and should not need any guarantors after the guarantorship tragedy experienced for 40 years. ..."
More English translation at ... http://www.parikiaki.com/2015/05/turkis ... in-cyprus/