US eyes military expansion in Greece amid strains with Turkey
Talks proceed on expanded operations, including using more air and naval bases
Turkey boosts arms to Syrian rebels as Idlib attack looms – rebel sources
The weapons, which have entered Syria in large quantities in recent days, include ammunition and GRAD rockets
Turkey begins constructing site for Russian S-400 missile system, despite US warnings
Turkey is slated to receive the S-400 next year and is expected to have the system ready for war by 2020