美媒爆料：如何应对战机“侵犯领空”，北约秘书长与爱沙尼亚总理曾“爆发冲突”

Group 1 - The core issue highlighted is the increasing division among NATO member states regarding responses to alleged Russian incursions into Estonian airspace, revealing limitations in collective defense capabilities [1][3] - Estonia protested against Russian aircraft allegedly violating its airspace and requested NATO to invoke Article 4 of the North Atlantic Treaty for consultations, which states that member countries should consult when a member's territorial integrity or security is threatened [3] - NATO Secretary General Jens Stoltenberg reportedly had a confrontation with Estonian Prime Minister Kaja Kallas over the repeated invocation of Article 4, warning that frequent alerts could undermine its effectiveness [3] Group 2 - Following Estonia's request, NATO held discussions regarding Article 4 at Poland's request, indicating ongoing consultations within NATO [3] - NATO member states conducted a series of flight training exercises, including low-altitude flights, in Estonian airspace from September 22 to 28 [3] - In response to Estonia's accusations, Russian presidential spokesman Dmitry Peskov dismissed the claims as unfounded, suggesting that Estonia's actions aimed to escalate tensions [3]