Recent Russian incursions into NATO airspace have sparked divisions within the alliance over how to respond, with Secretary General Mark Rutte clashing with Estonian Prime Minister Kristen Michal over the invocation of NATO's Article 4 clause. The tension comes after a series of provocative moves by Moscow, including missile-carrying Russian jets flying into Estonian territory and drones breaching Polish airspace. NATO allies are debating how to deter Russia without escalating into direct war.