The question buzzed through Kiev on Friday, then to capitals far beyond, to Warsaw, then Brussels, then Washington and Ottawa: Did Russia just invade Ukraine?

It's alarming to contemplate because of what it could mean – a divided Ukraine, a conflict that could spill beyond the country's borders and, almost surely, a return to something like Cold War footing between the West and Vladimir Putin's Russia.

Ukraine's new government declared on Friday that it had indeed been invaded, as gunmen in matching fatigues seized control of the two main airports in the southern region of Crimea and troop trucks with Russian license plates were seen moving around the peninsula. Ukraine's border service also reported an airspace incursion by at least 10 Russian military helicopters, an accusation that seemed to be supported by amateur video, and there were reports of movements by Russian transport planes and warships.

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Russia, which lost a key ally when Viktor Yanukovych was ousted as president and replaced by an interim government of pro-Western politicians last week, has refused to recognize the new interim government in Kiev. Moscow has strong influence in the Crimean peninsula, which was part of Russia until 1954, and still hosts the warships of the country's Black Sea Fleet.

In a televised address, interim President Oleksandr Truchynov said Russia had "sent forces into Crimea," and was planning to follow the same scenario it used 20 years ago in Abkhazia, a region of Georgia that broke away from the rest of the country with Russian encouragement and military support. Abkhazia remains isolated today, with only Moscow and a handful of other governments recognizing it as independent.

Kiev specifically appealed to the United States and the United Kingdom, the two parties that – along with Russia – had signed a 1994 pact guaranteeing Ukraine's sovereignty in exchange for the country handing its Soviet-era nuclear arsenal over to Russian control. It's likely the signatories of the so-called Budapest Memorandum never expected that 20 years later it would be a matter of war and peace.

"We are now deeply concerned by reports of military movements taken by the Russian Federation inside of Ukraine," U.S. President Barack Obama said in a brief statement he read to reporters at the White House. "The United States will stand with the international community in affirming that there will be costs for any military intervention in Ukraine."

Moscow kept its distance from the gunmen, saying they were volunteer members of "Crimean self-defence forces" that just happen to raise the Russian flag wherever they go. Vitaly Churkin, Russia's ambassador to the United Nations, said none of Russia's troop movements in Crimea violated the agreements between Russia and Ukraine governing the presence of the Black Sea Fleet.

Foreign Minister John Baird, after a day of meetings with Ukraine's post-revolutionary leadership in Kiev, said he was "tremendously concerned with some provocative actions" by Russia in the region but added that Canada was working with its allies "to ascertain fact from fiction."

He wasn't alone. Kiev-based diplomats from other NATO countries also struggled with what to tell their political leaders about was happening on the ground in Ukraine, asking for briefings from journalists who had recently been to Crimea what they thought was happening.

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Up close, the men who set up outside the commercial airport in the Crimean capital of Simferopol, as well as the Belbek military airport near the port city of Sevastopol, appeared to be professional soldiers. They wore matching fatigues, helmets, body armour and canteens, as well as freshly polished black boots.

At Belbek airport, the gunmen parked a green troop truck across the road and moved in practiced unison, fanning out on both sides of the road, whenever a vehicle approached, assault weapons at the ready. They bore little resemblance to the ragtag citizens' "self-defence forces" that have also appeared in Crimea in recent days. (The latter are primarily equipped with bats and construction hardhats.)

Driving between Belbek airport and Simferopol on Friday, The Globe and Mail counted 17 troop transport trucks driving on the same roads. Twelve had no license plates on them, but five had the black plates of the Russian military.

Multiple Russian armoured personnel carriers have also been spotted moving around Crimea in recent days.

Under a set of agreements related to the Russian naval fleet and two other small military bases on the peninsula, Moscow is supposed to seek Kiev's permission before any movements of troops or equipment between those facilities. Several local residents described the amount of Russian military activity as much greater than anything previously seen.

Russia is known to keep about 20 navy helicopters based near Sevastopol. However, the helicopters seen flying over Crimea in an amateur video appeared to be Mi-24 Hind gunships and Mi-8 transport helicopters. Russia's Itar-Tass news agency reported on Friday that more than 80 combat helicopters were taking part in a snap military drill Mr. Putin had ordered for this week and next along Russia's border with Ukraine.

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The takeovers of Simferopol and Belbek airports came one day after another band of pro-Russian gunmen seized the regional parliament building in Crimea. With the Russian flag flying from the roof, parliamentarians passed a motion calling for a May 25 referendum on Crimea's future as part of Ukraine. It's not clear what specific question Crimean voters will be asked to answer.

Ethnic Russians make up the majority in Crimea, and many are deeply suspicions of the new government as Kiev, which they see as dominated by Ukrainian nationalists, including some ultranationalists.

The new pro-Western government in Kiev, which came to power last week following violent protests that left at least 82 people dead, had already chosen the same date for a snap presidential election.

Further complicating matters Friday was the reappearance of Mr. Yanukovych. Making his first public remarks in nearly a week, he told a press conference in the Russian city of Rostov-on-Don that the new government was illegitimate and he was still president.

At one point, he said he would not ask Moscow to intervene militarily in Ukraine but later said, without elaborating, "I believe that Russia must and is obliged to act." He added: "Knowing the character of Vladimir Vladimirovich Putin, I am surprised he is so restrained and keeping silent."

Mr. Yanukovych, who said he was in Russia because he was concerned for his family's safety in Ukraine, said he had not met with Mr. Putin since arriving in Russia.

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The fact the Russian President has remained almost completely silent since the Ukrainian revolution – while keeping Mr. Yanukovych and the Crimean separatists at arm's length – is perhaps the most hopeful kernel of news.

While his officials, including Prime Minister Dmitry Medvedev have harshly condemned the transfer of power in Kiev, – and other prominent Russian politicians have flown to Crimea to voice support for the pro-Russian gunmen – Mr. Putin's silence suggests he may be keeping himself above the fray as a potential peacemaker.

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