Turkmenistan is the only former Soviet republic where all media is state-controlled.

Estonia, to date, is the only republic to officially approve use of its former flag, a blue, white and black banner.

Armenia is the only republic of the former Soviet Union that has a nearly-homogeneous population.

It is the only republic to have existed as an independent state, from roughly 1830 until 1918.

And done right, such a reduction would leave Russia as the only nuclear-armed republic.

Serbia is the only republic that includes autonomous provinces.

Macedonia was the only republic to secede peacefully from the Yugoslav state set up in 1918.

The only remaining republic yet to introduce official coinage is Belarus.

Oliver Cromwell headed the only republic that Britain ever had, from 1653 to his death in 1658.

Throw in the government of the only republic to successfully secede from the US.