Special counsel Robert Mueller's report has exposed the vast vulnerabilities of America's political system to outside interference, say experts, who have urged politicians, campaign teams and voters to view the sweeping account of Russian interference in the 2016 presidential election as a wake-up call.

"It is a story of failed immunity on the US side to outside interference - and aggressive Russian exploitation of the absence of democratic antibodies to fight off such manipulation," wrote Brookings Institution senior fellow in governance studies Benjamin Wittes on Lawfare, a widely read blog on national security issues.