Can you make a conclusion about " The USA's actions in the 1920's and 1930's " ?
One conclusion to this statement, which seems to be addressing the approach to foreign policy during the period, might be "...reflected an strong, if uneven, commitment to isolationism." On the one hand, the United States was fairly steadfast in its unwillingness to get directly involved in the affairs of the world, particularly Europe. Except for a few non-binding pacts and negotiations over the repayment of reparations and war debts, the United States remained generally aloof from European affairs during the 1920s. In the '30s, Roosevelt persistently criticized the Nazi regime, as well as those of Mussolini and Franco, but generally refused, for political reasons, to pursue an active policy in dealing with the threat that, in retrospect, they obviously posed.
On the other hand, the United States continued its policy of intervening militarily in Latin America in the 1920s and early 1930s, sending troops to such locales as Nicaragua and El Salvador to support American business interests there, and supporting the brutal dictator Rafael Trujillo in the Dominican Republic. Both Presidents Hoover and Roosevelt attempted to undo some of the ill will that developed as a result of these actions, with Roosevelt's "Good Neighbor Policy" in particular rejecting the use of force as a tool of diplomacy in the region. But the United States still continued to play a marked role in Latin America, a bit of a departure from its role in Europe, which was, ostensibly at least, isolationist.