During world war i the russian army was

WWI -- Russia. Russia entered the first world war with the largest army in the world, standing at 1,400,000 soldiers; when fully mobilized the Russian army expanded to over 5,000,000 soldiers (though at the outset of war Russia could not arm all its soldiers, having a supply of 4.6 million rifles).

Explanation:

when world war i broke out across europe in 1914, president woodrow wilson proclaimed the united states would remain neutral, and many americans supported this policy of nonintervention. however, public opinion about neutrality started to change after the sinking of the british ocean liner lusitania by a german u-boat in 1915; almost 2,000 people perished, including 128 americans. along with news of the zimmerman telegram threatening an alliance between germany and mexico, wilson asked congress for a declaration of war against germany. the u.s. officially entered the conflict on april 6, 1917.