Central Intelligence Agency officials have told members of the US Senate that Russian hackers tried to interfere with the US presidential election — with the specific aim of helping president-elect Donald Trump win. This is a frightening disclosure. The conclusion is much stronger than what was already acknowledged, that Russian hackers broke into the Democratic National Committee and provided the stolen documents to WikiLeaks. It demands a rigorous investigation by both Congress and the intelligence community, and is a matter of concern not just for the US but for all liberal democracies.

Any reset of US-Russian relations presaged by the arrival of a new administration in Washington must be put on hold until the issue has been resolved.

The response of the Trump team has been self-serving. It stated that “It’s now time to move on” and said the CIA “are the same people that said Saddam Hussein had weapons of mass destruction.” Mr Trump calls the CIA assessment “ridiculous” and “just another excuse” from partisan democrats. It is true that a full review of the hacks has not been completed, and the public has been given no new information. The extent of the hacks may turn out to be limited. The CIA may be mistaken. But it is wrong for Mr Trump to be dismissive and derogatory towards the intelligence agencies he will depend on as president; all the more so when the matter at hand is the integrity of American democracy.