"serious provocation" is a correct and usable phrase in written English.
You could use it in a sentence such as: "His comments were seen by many as a serious provocation."
"That was a very dangerous and serious provocation," said Milan Protic, a leading opponent of the government.
Park's spokesman described the launch as a "serious provocation" before attacking her main rival, Moon Jae-in, who has advocated unconditional talks with the North.
"If North Korea goes ahead and launches the rocket, it would clearly violate UN security council resolutions and pose a serious provocation," Abe said in parliament.
Mr. Aliyev, who succeeded his father as president in 2003, called the killing a "serious provocation against the state" and said an investigation was under way.
While the United States and South Korea have publicly said a launching would be a serious provocation, some American officials say it might also serve as a way for Mr. Kim to back away from a confrontation while saving face.
China summoned the US ambassador to Beijing in protest and accused the US of a "serious provocation" following US naval manoeuvres during which the guided-missile destroyer USS Lassen sailed close to a Chinese artificial island.
If the ship is found to have been torpedoed by North Korea, as many South Koreans suspect, it will amount to one of the most serious provocations from the North in recent decades.
Anything that happened to Miss Shepherd – from the everyday skirmishes she had with neighbours and passersby to the more serious provocations regularly visited on her by hooligans or the malevolent – all these were a distraction to me when I was trying to write.
He said the South now realised the North would not on its own abandon its nuclear programme, adding that tolerance would "spawn nothing but more serious provocations".
Speaking from the Venezuelan capital, he said there had been "serious provocations that could threaten his life", but gave no details.
So Russia has already committed serious provocations against other countries.
