Former vice president Walter F. Mondale charged Tuesday that President Reagan has not met one of the most important tests of his office--the wise leadership of the Atlantic alliance.

"In the last nine months," Mondale told the Foreign Policy Association in New York, "the United States has dangerously mismanaged relations with our European allies. We have sown doubt and confusion about our ability to act as a full partner with Europe. After careful study, I am convinced that the alliance is in more trouble today than at any times since the North Atlantic Treaty was signed."

In his first major foreign policy speech since being voted out of office, Mondale talked mostly in generalities to support his theme. He contended that Washington had basically exported unresolved U.S. economic conflicts to Europe and in so doing had weakened the allies' abilities to support defense.

He argued that instead of a common alliance on how to contain Soviet power and reduce confrontation, "there is today a great divide between the United States and most of its European allies" on such issues.

Noting the growing protest in Europe over U.S. arms policies, Mondale told the association that the Reagan administration has "put us in the astounding position of appearing that it is we, and not the Soviet Union," who are "unwilling to talk" about arms control.