The thesis examines escalation of international crisis involving both a state and a non-state actor. It takes as its starting point the following empirical anomaly. In the summer of 2006 Hezbollah kidnapped two Israeli soldiers. This set in motion a chain of events which ended in what is now called the Second Lebanon War. In October of 2000 Hezbollah however carried out an almost identical operation. The organization kidnapped three and in the process killed four Israeli soldiers, but this time in contrast no process of escalation followed. These two events will be studied as cases of international crisis. By integrating domestic politics into international relations, I will explain why the 2006 Olmert government made decisions so drastically different from the 2000 Barak government. Utilizing a controlled comparison design and game theory I will argue that the combination of a weak Israeli government that came under severe criticism from the Knesset, the shift in the regional balance of power and the information asymmetry that marked the interaction between Israel and Hezbollah together explain why the Hezbollah operation in 2006 escalation into a war, while the almost identical operation in 2000 did not.