Sentence:  According to U.S. law, <WSD>filibustering</WSD> was a violation of the Neutrality Law of 1818, which prohibited the organization within the United States of any armed force that intended to attack a friendly foreign power. The American government attempted, through the enforcement of this law, to prevent its citizens from <WSD>filibustering</WSD>, mostly by preventing potential <WSD>filibustering</WSD> groups from organizing and collecting arms for future operations. 
Meaning of the word marked with <WSD> tags:  To take part in a private military action in a foreign country.