The correct answer to this open question is the following.
The United States has continued to lead humanitarian assistance abroad through diplomatic ties with allies and friendly countries.
Examples of humanitarian assistance are the US intervention in Kosovo during President Clinton's administration, the assistance to poor families in Irak, after the invasion of Bagdag, the assistance to African hunger, its recent intervention in Syria to try to end the conflict there or its reaction to the annexation of Crimea by the Russians.