Talk:2014–16 Russian military intervention in Ukraine/Sandbox

Russia sent troops and military equipment into Ukraine in what has been termed a stealth invasion following the February 2014 Ukrainian revolution and Euromaidan movement, the flight and disputed impeachment of President Viktor Yanukovych  and the subsequent 2014 Crimean crisis. In February, during that crisis, unmarked soldiers gradually took control of the Ukrainian territory of Crimea, which Russia then annexed; London-based military experts said the soldiers were likely Russian special forces (possibly including Spetsnaz commandos) and airborne units, and although Russia initially insisted that Russian forces stationed in the area were not involved, Russian president Vladimir Putin admitted in April that Russian troops had been active in Crimea and said this had laid the ground for the referendum.

In August, unmarked troops and military vehicles from Russia also crossed into the Donbass region, escalating the Russian-backed war against Ukrainian forces there. Russia has distanced itself from allegations of military involvement in the Donbass, though the United States has accused it of being behind the unrest and war there, and videos of Russian soldiers captured in Ukraine, comments by rebel leaders such as Zakharchenko and statements such as that of the head of the Russian Union of Committees of Soldiers' Mothers, Valentina Melnikova (reported by Corey Flintoff of NPR) have established that Russian service personnel are fighting in Ukraine.

At the beginning of the insurgency, the prime ministers of Donetsk People's Republic and Luhansk were Russian citizens; they were succeeded by Ukrainian citizens by August. Many of the separatist fighters are Russian citizens, with many claimed to be former military personnel. The SBU claims key commanders of the rebel movement during this time, including Igor Strelkov and Igor Bezler, are Russian agents. American and Ukrainian officials said they had evidence of Russian interference in Ukraine, including intercepted communications between Russian officials and Donbass insurgents. Separatist leaders like Alexei Moskovoy visited Moscow and were evasive about who was supplying their weapons. There is also evidence that indicates the Buk missile system, widely believed to have been used to shoot down Malaysia Airlines Flight 17 on 17 July, came from Russia. In late August, NATO released satellite images which it said showed evidence of Russian operations inside Ukraine with sophisticated weaponry, and after the heavy defeat of Ukrainian forces by early September, it was evident Russia had sent soldiers and armour across the border and locals acknowledged the role of Putin and Russian soldiers in effecting a reversal of fortunes.

On 5 September, representatives of Ukraine, Russia, the Donetsk People's Republic and the Lugansk People's Republic signed the Minsk Protocol, a twelve-point agreement that implemented a ceasefire. On 10 September, Ukraine President Petro Poroshenko said most of the Russian forces had withdrawn from Ukrainian territory, and that this heightened the chances for a lasting cease-fire in the southeast. On 13 September, it was reported Russia had sent a convoy of aid into eastern Ukraine without inspection by Ukraine, claiming this convoy was part of the ceasefire agreement. NATO said Russian forces were still operating in Ukraine in unknown numbers, and the ceasefire was not working. NATO said Russian forces were repositioning to bring great pressure on Mariupol.

Several members of the international community and organizations such as Amnesty International have criticized Russia for its actions in post-revolutionary Ukraine, and condemned Russia, accusing it of breaking international law and violating Ukrainian sovereignty. Many countries implemented economic sanctions against Russia or Russian individuals or companies, to which Russia responded in kind. The Kremlin has tried to systematically intimidate and silence human rights workers who have raised questions about Russian soldiers' deaths in the conflict.