What has come between Donald Trump and Vladimir Putin?

The downturn in the US-Russian relationship, at odds with the warmth of the US presidential election campaign, could drive Russia into China’s arms, writes Josh Cohen

During his presidential election campaign, Donald Trump’s verbal affection for Russian president Vladimir Putin so puzzled the Washington establishment that some speculated that Mr Putin had either “recruited Mr Trump as an unwitting agent of the Russian Federation” or that Trump was simply a “useful fool” for the Russians.

But 100 days into Mr Trump’s presidency, this seems anything but true. After the US retaliated for the Assad regime’s chemical weapons attack in Syria, Washington and Moscow are engaged in a harsh war of words.