TheeconomicconsequencesforChinaofanewKoreanWar(3)

Retired Lieutenant-General Dave Deptula and Trump administration officials have hinted that such options exist and are being refined and readied to be used this year should diplomatic efforts fail.
Restrained response
How would China and Russia respond to allied military action? History suggests they would be restrained, but they would adopt a responsive posture, for example by placing their nuclear arsenals on high alert. China would be constrained by the recognition that US nuclear ballistic-missile submarines are standing by off the coast, ready to respond to any Chinese attempt at nuclear attack.
But what about lower-level “limited” responses such as dispatching “people’s volunteers” or aiding North Korea with materiel, weapons, intelligence and knowhow to prevent a US victory? Whether President Xi agrees or not may not matter to the People’s Liberation Army warlords and Chinese “local” governments making these decisions.
The United States would respond to Chinese intervention or that of Chinese elements (or other parties) swiftly and certainly. Unlike the first Korean War, when the US had few economic and political levers against Communist China, the People’s Republic of China in the 21st century is vulnerable to Western sanctions short of war.