NATO defence ministers will look Wednesday at shoring up the alliance's ability to counter Russian air incursions, as fears grow that Moscow is testing the West in a grey zone between war and peace.
Focus will also be on bolstering support for Ukraine as US Defense Secretary Pete Hegseth joins his 31 NATO counterparts with his boss, President Donald Trump, mulling the supply of long-range missiles to Kyiv.
The gathering in Brussels comes after Moscow rattled NATO with a series of high-profile airspace violations in Poland and Estonia that fuelled fears of conflict spilling over its border.
Those were followed up by a spate of mysterious drones that disrupted airports and flew close to military sites in a string of countries.
All this has added fuel to concerns that Russia is pushing th