What was Artcile X of the League Covenant and why was it so controversial?

Answer 1

Have you read it? If not now is the time:

The Covenant of the League of Nations was the source of much criticism. Article X of that document prescribed the use of collective security actions to guarantee the status quo in the postwar world. Lodge and others were disturbed by the prospect of having American soldiers called to protect the territorial integrity of other member states and serve under the command of foreigners in faraway places. Other critics pointed to the League’s voting procedures that assigned a single vote to the United States, but allowed six from the British Empire.



http://www.sparknotes.com/history/european/ww1/terms/term_35.html
http://en.wikipedia.org/wiki/Article_X_of_the_Covenant_of_the_League_of_Nations\
http://www.u-s-history.com/pages/h1339.html\

Answer 2

Here is the text of Article 10:
ARTICLE 10.
The Members of the League undertake to respect and preserve as against external aggression the territorial integrity and existing political independence of all Members of the League. In case of any such aggression or in case of any threat or danger of such aggression the Council shall advise upon the means by which this obligation shall be fulfilled

I think you can see why this would be controversial.
It says that if you join the league, you are responsible for the security of all the other members.

For the full text of the League of Nations Covenant:
http://www.yale.edu/lawweb/avalon/leagcov.htm