Why is humanitarian intervention a controversial issue?

This is a common 15 mark question in A2 Government & Politics Unit4D paper. For addressing the question correctly, firstly you need to define the concept of humanitarian intervention by giving couple of examples (NATO in Yugoslavia 1995, Kosovo 1999, Libya 2011). The term is controversial due to three main factors. Firstly, the biggest issue is the undermining of state sovereignty. In 1648, after the Thirty Years War, the Treaty of Westphalia was signed and countries agreed to respect each other's territorial rule and do not intervene in it as it would undermine state's sovereignty. Liberal critics argue that sometimes the concept of state sovereignty should be put aside when ethnic cleansing or a massacre is taking place in a country. Secondly, its controversial as sometimes states send troops due to their own national interests. In Somalia 1993, President Clinton sent US marines in order to make sure that Farrah Aidid would stop killing innocent civilians (but! Somalia is rich with raw materials and therefore critics argue that they intervened in order to get trade deals). Finally, the concept of humanitarian intervention is controversial as sometimes interventions may further worsen the situation in the country. (e.g. Libya 2011, NATO established "no fly zones", Gaddafi's regime was overthrown and now Libya is in total turmoil)