The operation, Steadfast Dart, comes as President Trump has been accused of undermining the alliance and will be watched closely to see how well the allies manage without their most important partner.

NATO Secretary General Mark Rutte drew stinging rebukes from across the continent over remarks alleging Europe can't defend itself without the aid of the US. While Europeans say the assessment is unjustified,

NATO Secretary General Mark Rutte has told Europe it should “keep on dreaming” if it thinks it can defend itself without the support of the United States.