You'll be able to make the most of your library catalog searches if you learn to use some basic patterns:
Foreign relations
United States AND foreign relations AND [country or region]
sample: United States AND foreign relations AND Iran
[country] AND economic conditions
[country] AND foreign relations
[country] AND politics and government
[country] AND social conditions
sample: Iraq AND politics and government
American National Government Policy
[topic] AND United States
[topic] AND government policy
[topic] AND history
[topic} AND political aspects
[topic} AND economic aspects
samples: immigration AND government policy
alien labor AND economic aspects