The European Union's unity, solidarity, and global reputation are in jeopardy due to various factors such as Greece's debt, Russia's involvement in Ukraine, Britain's efforts to redefine its relationship with the EU, and the issue of Mediterranean migration. Failing to address any of these challenges adequately would exacerbate the others, increasing the risks facing the overall "Project Europe". The immediate concern is Greece's potential default and the possibility of it leaving the euro currency, known as 'Grexit', which poses a significant threat to the idea of a closer union among European countries and peoples. According to a report by the European Policy Centre think-tank, a Grexit would have long-term consequences for the EU, setting a precedent and undermining the organization's purpose. While Greece only makes up a small portion of the euro zone's economic output and population, its recent state bankruptcy and reliance on bailouts totaling nearly 200 billion euros has had a significant impact on the EU's reputation. The aftermath of the Greek referendum has led to tensions in Brussels, with different parties pointing fingers and offering various explanations for the crisis. Despite the uncertainty surrounding Greece's future, it has already demonstrated that the idea of an unbreakable membership in the euro currency is flawed. With potential efforts to strengthen the remaining members of the euro zone, such as addressing design flaws in the monetary union, there may be challenges in gaining consensus, particularly from Germany. The Greek situation will serve as a reminder for markets in future economic downturns within the euro zone. Destabilizing Greece's economy could have severe consequences, including causing suffering and financial losses for European taxpayers. Additionally, it could worsen Europe's existing crises and destabilize the fragile southern Balkans. With tensions already high in the eastern Mediterranean due to various conflicts and disputes, a weakened Greece may seek assistance from Russia. This could lead to Greece vetoing EU sanctions against Moscow or offering access to naval facilities once used by the United States. Greece is also facing challenges with an influx of refugees from conflicts in the Middle East, who are seeking asylum in other EU countries. Imagining a scenario where a government expelled from the euro zone uses migrants to put pressure on EU countries is not difficult. The issue of "boat people" has caused division within the EU, with frontline countries like Italy criticizing their northern and eastern counterparts for not showing solidarity by refusing to share the burden of refugees. Britain has also declined to take in refugees. The failure to resolve Greece's debt crisis after five years has made the EU appear weak and divided to leaders like Russian President Vladimir Putin and Chinese President Xi Jinping. Brussels officials admit that the euro zone crisis has led to a return to national decision-making on certain policies and weakened Europe's "soft power" of supranational governance based on rules. The EU's position in global trade and climate change talks has been undermined, and there are concerns about the potential consequences of Britain's push to renegotiate its membership terms and hold a referendum by 2017. The EU faces the risk of losing a significant economy, financial center, and military power if Britain chooses to leave. While polls show support for staying in the EU, there is still apprehension in Brussels due to past inaccuracies in UK polls. Since winning, Cameron has faced challenges from Eurosceptic rebels in his Conservative party. A potential Greek economic crisis, whether in or out of the euro zone, could bolster arguments that the UK economy is linked to a failing system. Russia's historical animosity towards Britain, which is viewed in Moscow as the US' closest ally, could benefit from the UK leaving the EU. This could undermine efforts within the EU to address Russian actions in Ukraine and Georgia, as well as weaken ties between the UK and the EU, despite remaining in NATO. This could give Putin an advantage in negotiations with German Chancellor Angela Merkel, who has been leading European efforts to support Ukraine. Rem Korteweg from the Centre for European Reform likens the interconnected crises to the four horsemen of the apocalypse mentioned in the Book of Revelation, symbolizing conquest, war, famine, and death as harbingers of a "day of judgment". In an essay, Korteweg expressed that EU leaders will struggle to control these crises, warning that without a unified European response, chaos, instability, and blame will persist within the EU.