The US, UK, NATO and CIA have released hundreds of official documents relevant to all the events leading up to the Greek Coup, and invasion by Turkey. They have released a lot of information of their involvement. The US in particular has released information which incriminates the Kissinger/Nixon administration.
So while the US has been quite open, why is Greece not so open?
I believe the infamous Cyprus File is still classified after nearly 40 years. Why not open this file?
What are the contents of this file? What is Greece trying to hide?