In 1995, Sweden's accession to the European Union (EU) brought about a significant transformation in its foreign policy, leading to a more proactive engagement in global affairs. This shift became particularly evident during the Kosovo War of 1998-1999, wherein the Swedish government advocated for a more active approach through cooperation missions and rallied around the EU flag to advance its leadership aspirations within the Union via foreign policy means. This approach deviated from relying solely on diplomatic efforts, as observed in the ongoing Russian invasion of Ukraine in 2022. In this context, the Swedish government leveraged its presidency in the EU to assume a leadership role and rally EU member states in support of the EU flag, enabling sanctions against Russia and providing military and financial aid to Ukraine. This research employs an in-case comparative study, focusing on the international application of the "Rally around the flag" effect instead of its more commonly examined domestic manifestations. The theoretical framework of securitization guides the investigation into how Sweden rallies around the EU flag, the factors shaping Sweden's response and approach during the Russian invasion of Ukraine relative to the Kosovo War, and the discernible differences between their responses during the timeframes of 1995-1999 and 2022-2023. To achieve this, a qualitative discourse analysis is conducted, delving into Swedish governmental official documents, statements, and speeches pertaining to the Kosovo War and the conflict in Ukraine. The analysis reveals that Sweden exhibited a rallying effect around the EU flag in both crises, demonstrating diverse manifestations of support. During the Kosovo War, the Swedish government assumed an active role, manifesting its support through international peacekeeping cooperation missions in the Balkan region, particularly in Kosovo, with the aim of safeguarding its leadership interests. Conversely, in Ukraine, the Swedish government adopted a proactive role in rallying behind the EU flag, utilizing its EU presidency to unify EU member states in support of the EU flag, implement sanctions against Russia, and provide military and financial assistance to Ukraine, thus securing its leadership position. Hence, this thesis aims to make a substantive contribution toward comprehending the "Rally around the flag" effect in an international setting.