We are closer than ever to arresting Putin, but the US must play its part | Gordon Brown

This summer will be a crisis point for the Russian president, as demands for action intensify

A new grassroots campaign calling for the Russian president, Vladimir Putin, to be tried for war crimes represents an escalation in the demand for justice for the people of Ukraine. Already 2 million have signed a petition calling for Putin's indictment.

Now, in the run-up to August's Brics summit (Brazil, Russia, India, China and South Africa) to be held in Johannesburg, more than half a million have already called for the South African authorities to put him in prison if he flies in to their country. This public pressure comes as European leaders meeting in Reykjavik have intensified their call for coordinated intergovernmental action to find a way to punish Putin for his crimes.