Banned INF missile launch
© US Department of Defense/Scott Howe
Conventional ground-launched cruise missile test, San Nicolas Island, CA, August 18, 2019
Reaction out of Moscow and Beijing was swift after the US revealed Monday that the Pentagon successfully tested a ground-launched cruise missile with a range of over 500km for the first time in a post-INF treaty world.

Russia warned of a new "costly arms race" which it says it's seeking to avoid. Russia's deputy foreign minister, Sergei Ryabkov, told state news agency TASS:
"The US has obviously taken a course towards escalation of military tensions. We won't react to provocations. We will not allow ourselves to get drawn into a costly arms race."
Interestingly, given the Pentagon test of a previously banned land-based intermediate cruise missile - which took place at a range in California on Sunday - came a mere 17 days after the final and formal US pullout of the landmark Intermediate-Range Nuclear Forces treaty, Ryabkov further said this was clear evidence that the United States had already been in breach of the treaty prior to its official end, given the technology development and extensive preparations that went in to such a test.

Echoing past statements of Putin, Ryabkov also said that Moscow would not use such missile systems "if and when we get them, as long as the US does not deploy them anywhere in the world".

Meanwhile, Chinese foreign ministry spokesman, Geng Shuang, also slammed the test, warning of a new Cold War given the persistent US mentality. He said international fallout from the test would have "serious negative impact" on the global security order:
"This measure from the US will trigger a new round of an arms race, leading to an escalation of military confrontation." America must "let go of its cold war mentality...do more things that are conducive to...international and regional peace and tranquillity."
Chinese and Russian concerns are also driven by the fact that earlier this month US defense secretary Mark Esper said the US is seeking to station previously banned missiles in the Asian-Pacific region. He also in comments specifically invoked the 'Russian threat' as requiring a robust missile deployment:
"Now that we have withdrawn, the Department of Defense will fully pursue the development of these ground-launched conventional missiles as a prudent response to Russia's actions."