US Senator John McCain yesterday accused Russian President Vladimir Putin of allying himself with tyrants and ruling through violence and repression, in a scathing retort to a New York Times opinion piece by Putin earlier this month. In an editorial published on news website Pravda.ru , McCain criticised the Russian leader's policies at home and in Syria, where Putin has repeatedly protected President Bashar al-Assad. "(Putin) is not enhancing Russia's global reputation. He is destroying it. He has made her a friend to tyrants and an enemy to the oppressed, and untrusted by nations that seek to build a safer, more peaceful and prosperous world," wrote the senior senator from Arizona, who is also a leading Republican voice on military affairs. US-Russia ties are at one of their lowest points since the Cold War as tensions over human rights and the fate of fugitive ex-US intelligence contractor Edward Snowden, to whom Russia awarded asylum, have added to tensions over the Syrian conflict. Putin's opinion piece took issue with US President Barack Obama's claims of "American exceptionalism" and said a military strike against Assad could escalate the conflict that has already killed more than 100,000 people. McCain has been critical of Putin's domestic policies, including Moscow's response to a protest movement that emerged in 2011. "President Putin and his associates ... don't respect your dignity or accept your authority over them. They punish dissent and imprison opponents. They rig your elections. They control your media," McCain wrote. McCain also made reference to whistleblower Sergei Magnitsky, who died in pre-trial detention after accusing officials of a US$230-million. He also said that the members of the protest punk band Pussy Riot, two of whom are serving time for a protest against Putin in a Moscow cathedral, had been convicted on political grounds.