Since the war began in 2022, Russia's military activities, which were confined to Ukraine, are now rapidly spreading beyond the borders of North Atlantic Treaty Organization (NATO) member states. In September, Russian unmanned aerial vehicles (UAVs) and fighter jets repeatedly intruded into the airspace of Poland, Romania, and Estonia. Tensions in Europe escalated sharply as airports and air force bases in Denmark and Norway were temporarily shut down following the appearance of drones presumed to be Russian.

NATO has warned that it will use all means to defend against further Russian airspace violations. Indeed, Article 4 of the NATO Treaty was invoked at the request of Poland and Estonia, leading to emergency consultations. However, Article 5, which would treat a Russian intrusion as an attack on the entire alliance and enable a military response, was ultimately not invoked. A full-scale military response was not considered.

This is the core of the dilemma facing Europe. It is inefficient to deploy expensive fighter jets or interceptors every time to shoot down a UAV that costs only a few thousand dollars. The more serious problem is that a decisive response, such as shooting down a Russian fighter jet, could potentially lead to a risk of escalation that Europe can ill afford. Although NATO has vowed a 'firm response' to further provocations, this pledge is bound to sound hollow given the practical constraints.

These Russian intrusions into NATO airspace are a classic example of 'Salami Tactics.' This approach begins with small intrusions that don't provoke a reaction, like thinly sliced sausage, gradually raising the level of intensity without triggering a dramatic provocation that would necessitate a firm response. Through this tactic, Russia minimizes the risk of provocation, repeats low-intensity provocations, and attempts to slowly cook the adversary, like a 'frog in boiling water.'

Russia's Salami Tactics pursue three main objectives. First, they place the risk of escalation on Europe. Second, they induce division among NATO member states regarding the level of response. Third, and ultimately, they aim to weaken European support for Ukraine, thereby creating and solidifying an environment favorable for an end to the war.

The problem is that this process erodes the clarity of the 'red line' of 'avoiding direct conflict' between NATO and Russia, a line upheld since the Cold War era. Warnings that the repetition of small provocations deepens mistrust among major powers, stiffens foreign and security policies, and paradoxically instills a confidence that 'war is inevitable' — potentially sowing the seeds of a major conflict — should not be taken lightly. Like the series of military crises immediately preceding World War I in 1914, small provocations carry the risk of triggering a self-destructive security dilemma.

NATO has expressed its firm resolve against Russian provocation but is constrained by the realistic imperative to avoid military escalation. Russia is exploiting this gap, continuing low-intensity provocations to test Europe. The dilemma facing Europe now is that a military choice to avoid the fate of the 'frog in boiling water' could potentially open the door to an even harsher crisis, and this will be a major challenge testing the cohesion and strategic response capability of the NATO alliance.