Bachelor Thesis from the year 2015 in the subject Economics - Finance, grade: 5, University of Zurich, language: English, abstract: This bachelor thesis discusses the sustainability of government debt on a theoretical level with the model of the government budget constraint and its application in a case study. Therefore, the situation of Greece is used as a prime example for the current sovereign debt crisis in the European Monetary Union. It points out with quantitative data, what has led to the high public debt in Greece and what are the consequences of this debt accumulation. For this the sustainability and the development of government debt and its determinants will be analysed. In conclusion, it discusses the options to escape of this sovereign debt crisis for Greece and the European Monetary Union as a whole. In March 2012 Greece received another bailout loan of 144.7 billion euro from the European Financial Stability Facility (EFSF) and 19.8 billion euro from the IMF in several tranches until 2014 after a worsening recession and the missing implementation of the conditions. In July 2015 the European Commission arranged to mobilise more than 35 billion euro until 2020, while they already paid out up to this point 4.4 billion euro (European Commission 2015). Still the problem has not been solved yet and Greece is still not able to get control of its debt by itself. The government debt is a relevant topic in economics and has become even more relevant since the outbreak of the European sovereign debt crisis. Further research in the issue of government debt could help us to understand how government-debt crisis develop, how the current sovereign debt crisis may be solved as well as how we could prevent from future crises. To understand the problem of high debt, we also need to understand the necessity of public debt, the arithmetic behind it and its implications on the economy of a country and the whole economic system.