How did their rejection of this idea change US foreign policy?​

After the war the U.S. economy slowly declined into recession while anti-immigration sentiments continued to peak. ... During Woodrow Wilson's presidency, the United States briefly shed its isolation-based foreign policy in order to defend democracy on a global scale

Explanation:

montesquieu took the view that the roman republic had powers separated so that no one could usurp complete power. in the british constitutional system, montesquieu discerned a separation of powers among the monarch, parliament, and the courts of law.