What stated that the US would act as international policemen, defending the Western Hemisphere in the imperial age?This was an addition to the Monroe Doctrine.​

Roosevelt Corollary

Explanation:

The Monroe Doctrine of 1823 forbade European powers from colonizing any more territory in the Americas or attempting to increase their influence there. Theodore Roosevelt saw this as too passive especially when Venezuela was in danger of being invaded by European powers for the debt it owed.

In response, President Roosevelt, seeking to forestall this, added the Roosevelt Corollary to the Monroe Doctrine and stated that the U.S. would step in to fulfil the credit obligations of other countries in the Americas if the security of the Americas is threatened. The U.S. would in effect, act like an international policeman whose job was to defend the Western hemisphere.

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.  

north atlantic treaty organization.