Introduction
In a moment of profound and accelerating transformation in the international order, whose full implications remain contested, a high level of fragmentation is emerging in a diffuse and regionally differentiated logic. The shift towards a new multipolarity and the lack of international leadership pose a great challenge in terms of stability and unity, also to and within the Transatlantic Alliance. As a matter of fact, the structural change underway is different from the traditional tensions that NATO had to navigate in the past. The current international system is becoming more competitive, but to some extent no single actor -or coalition of actors- retains the capacity to set the rules unilaterally by enforcing them consistently and fully deterring the challenges. This trend is quite visible in many strategic theatres where the Western influence has been collapsing and regional powers are trying to navigate the situation by pursuing their own regional security through new cooperative approaches. The American security guarantees no longer function even within Europe, whose collective security is now undermined by the Trump Administration’s ambitions to recalibrate its posture towards the “America First” unilateralist logic aiming to make the U.S. as an “indispensable nation” unconstrained from multilateral frameworks and alliance obligations.
In this perspective, the U.S. acts as a dominant power in any priority theatre of interests, while the reciprocal obligations to allies are declining. Thus, Trump looks at NATO as a sort of service arrangement to be renegotiated, not as the institutional expression of a shared security community. Paradoxically, this approach towards unilateralism de facto provides regional and middle powers compelling arguments for a strategic diversification. The outcome is a changing world where U.S. power is still a great power, but the American leadership is increasingly contested and therefore declining by generating systemic instability. The consequences for the Western block are quite crucial. Although the Transatlantic Alliance architecture remains institutionally intact, its internal political cohesion is under unprecedented strain. The fractures are indeed multiple and they mutually reinforce. The main issue lays on the deep friction between the U.S. and its European allies over burden-sharing, strategic priorities and the scope of collective obligations. This rift is creating great alarmism in Europe, which is currently not ready to cope with the current challenges. Within Europe itself another fracture has been emerging, namely between states whose primary threat perception is continental and eastward-facing and those whose security priority direction is towards the south where the main challenges are shaped by migration, energy and the instability of the Mediterranean basin rather than by the Russian threat.
