President Barack Obama has promised a new US foreign policy based on "collective action" with allies abroad.
The US would still lead, he told graduates at the US Military Academy at West Point, New York, but would avoid the "costly mistakes" of the past.
He announced a $5bn (£3bn) fund to fight global terror and promised the US "must not create more enemies than we take off the battlefield".
Under attack for a weak foreign policy, he hailed progress in Ukraine and Iran.
"Sceptics often downplay the effectiveness of multilateral action. For them, working through international institutions, or respecting international law, is a sign of weakness. I think they're wrong."
The end of the combat mission in Afghanistan at the end of the year would free up resources to tackle emerging threats elsewhere, such as a new $5bn "terrorism partnership fund" to help other countries fight extremists.