overt aggression

基本解释

Our intervention in Korea in 1950, though frustrating and ill thought-out, showed our adversaries we were willing to shed blood to stop their overt aggression.
FORBES: The Wilsonian UN--R.I.P
For a prolonged commitment of financial isolation by China and South Korea, the DPRK would have to either test a nuclear weapon or carry out some type of overt aggression in the region.
CENTERFORSECURITYPOLICY: Center for Security Policy Contain and Transcend: A Strategy for Regime Change in North Korea Page: 7
Given the past century's history, it's understandable that they might initially blanch at the notion of our attacking first rather than responding to an overt, unmistakable act of aggression.
FORBES: Fact and Comment