General Milley cannot undermine civilian authority. The US is not a military junta | Lt Col Daniel L Davis (ret)

A new book claims the US's top military officer secretly told the Chinese military he would warn if Trump ordered an attack. His reasons don't matter - he must be relieved of command

On Tuesday, the Washington Post published a bombshell drawn from a forthcoming book by the journalists Bob Woodward and Robert Costa: during the final days of Donald Trump's presidency, Gen Mark Milley, the chairman of the joint chiefs of staff and the US's highest-ranking military officer, called the senior ranking general of the Chinese military and offered to warn him in advance of any American military action against China.

Milley, who reportedly believed that Trump was unstable and might launch a politically motivated military operation, contacted the Chinese without the knowledge of the White House. He no doubt thought that his decision was for the greater good. But if he did indeed negotiate with a foreign military rival without authorization, he violated the longstanding American political tradition that the military is subordinate to elected civilian leaders.