Today, the Baltic Sea has become the epicenter of the European crisis. The Baltic Sea is the only region where NATO has a land border with Russia, increasing the region's sensitivity. The slightest incident can turn into a full-blown war in the region. Russia's complex security challenges, the region's geopolitical situation, and the Baltic states' defense vulnerabilities have raised the need to revive NATO's military presence and strengthen deterrence against Russia. In the light of interpretive structural modeling, this study seeks to answer the question of what effect Russia's escalating activities in the Baltic Sea have had on the effectiveness of NATO's deterrence strategy in the region. Given the theoretical framework of broad deterrence, it hypothesized that Russia's security strategy in the three areas of conventional, nuclear, and hybrid threat had led NATO to move toward broad deterrence based on the threat of punishment and denial. However, both types of deterrence do not have the quantity and quality necessary to fully contain Russia in the region, as in the Cold War. In order to measure efficiency according to the research method and its extended formulation, the indicators of credibility, communication, and capability are used. The findings show that deterrence through punishment is much more pronounced than deterrence through denial and that the normal state of deterrence in NATO is highly vulnerable to Russia. Weaknesses in capability and communication have also led to the fragility of NATO's deterrent credentials in the region, making the Baltic Sea very sensitive and critical.
