What do many believe to be the U. S.'s biggest foreign policy failure in recent years?

Many believe that the U. S. has not given enough financial aid to the countries of Africa.

The American foreighn policy has failed in the past to use diplomacy and negotiation to further its goals.

The lack of military assistance to those who are fighting Islamic extremists has been a major political failure.

Abandoning those living under brutal regimes and denied human rights is seen as a past foreign policy flaw.