The reach of the US lethal drone programme is extensive and the USA relies heavily on assistance from many States. Since taking office, President Donald Trump has reportedly made changes to US policy on the use of force outside areas of conflict. Combined with the current administration’s reported dramatic expansion in lethal drone operations, there is a real risk of an increase in unlawful killings and civilian casualties. This report examines the role played by the UK, Germany, the Netherlands and Italy and analyses whether assistance provided by them could be aiding potentially unlawful US drone strikes in violation of international law.