Senior Nato officials have raised concerns that attempts by Greece to forge a defence pact with Moscow could seriously undermine efforts to present a united front against further acts of Russian aggression.
Maintaining security in eastern Europe and former Soviet Union states is likely to dominate the Nato summit when leaders of the 28-member alliance meet in Warsaw on Saturday.
The summit is the first meeting of Western leaders since Britain’s Brexit vote in last month’s referendum, and Nato leaders are keen to demonstrate the vote does not signal divisions in Europe that could be exploited by the Kremlin.
But in what will be US President Barack Obama’s last Nato summit before he leaves the White House, Nato officials are raising concerns about deepening defence ties between Greece and Moscow which they fear could undermine attempts by Nato to present a united front against Russia.
Nato’s concerns relate to last month’s announcement by Panos Kammenos, the Greek defence minister, when he unveiled a new partnership with Russia to manufacture Kalashnikov rifles.
The Greek government says the deal is vital to prevent the collapse of the country’s defence industry. But in order for the deal to go ahead Moscow is insisting that Greece must first persuade its Nato partners in Europe to lift the economic sanctions imposed after Russia’s illegal annexation of Crimea in 2014.
Mr Kammenos, the leader of the Right-wing anti-austerity Independent Greeks party, is viewed with suspicion by many Nato leaders following a series of outspoken comments.
Last year he threatened to unleash “a wave of millions of economic migrants” and jihadists into Europe unless the EU backed down on austerity demands, and caused deep offence to Germany by claiming “Europe is governed by German neo-Nazis”.
But it is Greece’s deepening defence ties with Moscow that are causing most concern for Nato officials.
One said: “It is essential that Nato leaders present a united front against Russia at the Warsaw summit if we are to deter further acts of Russian aggression in Europe.
“But the fact that a strategically important Nato country like Greece is trying to build its own relationship with Moscow could seriously undermine the alliance’s ability to present a united front to deter further acts of Russian aggression.”
Vladimir Putin, the Russian president, has made no secret of his satisfaction at Britain’s decision to leave the EU, which he hopes will lead to further divisions in Europe that will allow him to increase Russian influence over former Soviet countries in eastern Europe.
Mr Kammenos, whose party joined forces with the Left-wing Syriza party of prime minister Alexis Tsipras to form a coalition government, was the only Western politician to attend the 4th Moscow International Security Conference held in April, when he claimed the EU’s sanctions had “been a disaster both for Russia and the EU”.