Military chiefs from the twenty-nine NATO member countries are in Brussels today.
Their advice will prepare the ground for next month’s meeting of Alliance Defence ministers.
Then, as now, Russia is likely to be the main focus of discussion.
Only this week the Royal Air Force scrambled Typhoons to intercept two Russian bombers when the aircraft were spotted over the North Sea close to UK airspace.
Such incidents have risen sharply and so too has the tension since Russia’s annexation of Crimea.
Moscow’s suspected involvement in the Ukraine conflict is another of NATO’s concerns; the Kremlin has ordered an upgrade of Russian military capabilities.
Its nuclear stockpile is to include new more powerful intercontinental ballistic missiles, which has unnerved Eastern allies on Russia’s border.
As well as this, Turkish president Recep Tayyip Erdogan has urged NATO to take a stand against the United States over its plans to form a Kurdish-led border security force in Syria.
Addressing his ruling party's deputies, the Turkish president protested over the proposed formation of the 30,000 strong Kurdish-led border force.
Ankara believes Syrian Kurdish militias to be terrorists and has previously threatened to launch a military offensive against the groups.
Mr Erdogan questioned NATO's stance on the issues saying:
"Hey NATO! You are obliged to make a stance against those who harass and violate the borders of your members."
Tuesday comments follow Mr Erdogan's accusation that the United States is creating an "army of terror" in Syria along the border with Turkey. He then vowed to crush the force.
Turkey's military chief is set to discuss the issue further in Brussels.