Duels fell out of favor in the 19th century. Evidently, nobody told Igor Plotnitzky. The newly elected head of the Luhansk People's Republic challenged Ukrainian president Petro Poroshenko on Wednesday in an effort to resolve differences between the two countries.

Poroshenko has yet to respond.

Generously, Plotnitzky will allow his Ukrainian counterpart to choose the weapon, and he has called for ten witnesses and ten members of the media to be on hand.

Showing an instinct for good reality programming, Plotnitzky added that he "would not be against the duel being shown live on TV."

The Luhansk People's Republic and the neighboring Donetsk People's Republic broke away from the rest of Ukraine in April, two months after protesters drove the pro-Russian president Viktor Yanukyovich from office. Ever since, the Russian-speaking region has struggled as a semi-autonomous enclave dependent on Russian financial and military assistance. Plotnitzky was elected as Luhank's president earlier this month in elections dismissed as "farcical" by Ukraine and the United States.

Meanwhile, Russian president Vladimir Putin welcomed a new U.S. ambassador in Moscow on Wednesday. In a letter to Putin, the ambassador, John Tefft, acknowledged "serious differences over Russia's policy in Ukraine." Putin welcomed the new ambassador but called for the United States not to "interfere with Russia's internal affairs."

Tefft, whose predecessor Michael McFaul departed in February after being "followed, harassed, and demonized on Russian state television" during his two years in Moscow, now must navigate one of Washington's most contentious diplomatic relationships. Presidents Putin and Obama recently met for the G20 summit in Australia, where their exchange was characterized as stiff and awkward. Returning to Russia, Putin quipped:

"You can accomplish a lot more with politeness and weapons than just with courtesy alone."

Not to mention duels.