A battle appears to be looming within the West's most important military alliance.

The two NATO members with the largest armies are in dispute over weapons from Russia.

The US is threatening sanctions against Turkey for buying the Russian S-400 anti-missile system, placing Russian weapons inside NATO territory.

Washington had warned that if the sale went ahead, Turkey would be kicked out of a programme to build its new F-35 warplane, and Turkish pilots learning to fly the jet would be sent home.

Why is the sale so controversial? And could Turkey be risking its position in the NATO military alliance?

Presenter: Martine Dennis


Osman Sert - research director at the Ankara Institute and former adviser to Turkish Prime Minister Ahmet Davutoglu

Anna Matveeva - visiting senior research fellow at King's College London

Marko Mihkelson - member of the Estonian parliament who serves as the deputy chair of the Foreign Affairs Committee

Source: Al Jazeera News