"According to Chapter VII of the United Nations Charter, only the UN Security Council has a mandate by the international community to apply sanctions (Article 4

"According to Chapter VII of the United Nations Charter, only the UN Security Council has a mandate by the international community to apply sanctions (Article 41) that must be complied with by all UN member states (Article 2,2)." https://en.wikipedia.org/wiki/International_sanctions https://en.wikipedia.org/wiki/International_sanctions For the US, congress is supposed to approve of wars but that has not always happened either. "It has been alleged that the War Powers Resolution has been violated in the past – for example, by George W. Bush invading Iraq in 2003 or by President Bill Clinton in 1999, during NATO bombing of Yugoslavia." https://en.wikipedia.org/wiki/War_Powers_Resolution https://en.wikipedia.org/wiki/War_Powers_Resolution