The European Union's unity, solidarity, and global reputation are in jeopardy due to various factors, including Greece's debt crisis, Russia's involvement in Ukraine, Britain's desire to alter its relationship with the EU, and the issue of Mediterranean migration. Failing to effectively address any of these challenges would exacerbate the others, increasing the risks facing the overall "Project Europe". Of these challenges, Greece's potential default and the possibility of it leaving the euro currency, known as 'Grexit', pose the most immediate threat to the long-held idea of a united Europe. According to Fabian Zuleeg and Janis Emmanouilidis of the European Policy Centre think-tank, the long-term consequences of Grexit would have a significant impact on the EU as a whole, setting a precedent and further weakening the EU's fundamental purpose. Even though Greece only makes up a small portion of the euro zone's economy and population, its declaration of bankruptcy after receiving two bailouts totaling nearly 200 billion euros has had a significant impact on the EU's reputation. The blame game has already begun, with Greeks pointing fingers at Germans, others blaming Greeks, and Keynesian economists criticizing austerity measures. Despite the uncertainty surrounding Greece's future, it has already proven that the idea of an unbreakable single currency is flawed. EU officials may now focus on strengthening ties among remaining members to prevent similar crises in the future, but opposition from Germany may hinder any progress on joint government bond issuance. This Greek crisis will serve as a reminder to markets when the next economic downturn hits the euro zone. Destabilizing Greece economically could have far-reaching consequences, not only causing suffering and financial losses for European taxpayers but also exacerbating Europe's other crises and destabilizing the fragile southern Balkans. With existing tensions in the eastern Mediterranean region due to various conflicts and disputes, a collapsed Greece might seek assistance from Russia, potentially impacting EU sanctions against Moscow or offering access to naval facilities formerly used by the United States. Additionally, Greece is currently dealing with an influx of refugees from conflicts in Syria and Iraq, who are seeking passage to more prosperous countries in Europe, further straining the already cash-strapped Greek authorities. Imagining a scenario where a government expelled from the euro zone uses migrants to pressure EU countries is not difficult. The "boat people" crisis has caused division in the EU, with Italy and other frontline nations criticizing their northern and eastern counterparts for lacking solidarity in refugee support. Britain has also declined to accept refugees. The unresolved Greek debt crisis, after five years of negotiations, portrays the EU as weak and divided to leaders like Russian President Vladimir Putin and Chinese President Xi Jinping who seek to increase their influence. Brussels officials admit that the euro zone crisis has led to more national decision-making on certain policies and weakened Europe's model of rules-based supranational governance. The EU's position in global trade and climate change talks has been compromised due to Britain's potential exit from the EU. This uncertainty is causing concern in Brussels, as the loss of the UK could mean losing a major economy, financial hub, and military power. Despite polls indicating majority support for staying in the EU, there is still anxiety over the potential consequences of Britain's renegotiation and referendum plans. The unpredictability of the situation has created a sense of unease in European capitals. Ever since his win, Cameron has faced opposition from Eurosceptic members of his own party. The ongoing Greek economic crisis, whether within or outside the euro zone, could support the argument that the UK economy is tied to a failing system. Russia's historical animosity towards Britain, which is viewed in Moscow as a close ally of the US, could lead Putin to welcome the UK leaving the EU. This move would weaken the EU's ability to respond firmly to Russian actions in Ukraine and Georgia, and would also separate Britain from its close relationship with the US, even though it would still be a part of NATO. This could potentially give Putin more leverage in negotiations with German Chancellor Angela Merkel, who has been leading European efforts to resolve the situation in Ukraine. Rem Korteweg from the Centre for European Reform likens the current crises to the four horsemen of the apocalypse in the New Testament, representing conquest, war, famine, and death. He believes that if the EU's leaders cannot find a solution, chaos and instability will persist within the EU.