Which nation faced military attacks starting in 2022, leading to increased NATO membership applications?

The correct answer is Ukraine because, beginning in February 2022, Ukraine faced a significant military invasion from Russia, which prompted a reaction both domestically and internationally. As the conflict escalated, Ukraine sought greater security guarantees and support, leading to its appeal for NATO membership. The invasion starkly highlighted the challenges of national sovereignty and security in Europe, prompting several countries to reconsider their defense strategies and alliances.

In the wake of these events, other nations in the region also began to express interest in NATO membership, fearing similar threats. However, the immediate military attacks and the consequent push for NATO membership applications were directly tied to the situation in Ukraine, making it the focal point of the response by nations seeking greater security coordination through NATO.