This thesis focuses on the inability of the United Nations Security Council to address an issue of international peace and security in the presence of a veto cast by a permanent member. In particular, we identify the conditions under which the UN Security Council becomes "paralyzed" because of the veto power and analyze how draft resolutions develop after being vetoed. We identify the total of four post-veto scenarios that allow to trace the development of these vetoed draft resolutions, fully investigating the first post-veto scenario: a previously vetoed draft resolution becomes adopted by the UN Security Council, but its text does not contain any points that would provoke a negative reaction of a vetoer. However, we also note that there are agreements, and thus we are interested in how they have come about. In the next section, the concept of post-veto scenarios is discussed in details. The thesis proceeds as follows. Chapter 1 analyzes all the twelve draft resolutions vetoed by Russia and China regarding the crisis in Syria, along with relevant Security Council meeting records. In Chapter 2 we cover all the documents the UN Security Council agreed on with the purpose of addressing the Syrian crisis. Chapter 3 examines the first post-veto scenario involving the adoption of a "weaker" resolution instead of a vetoed one in the UN Security Council. Lastly, we conclude with final remarks.