by Rachel Salisbury 

Following months of political unrest in Ukraine regarding Russia’s annexation of Crimea, fear of a Russian invasion into mainland Ukraine is mounting. On Thursday, the North Atlantic Treaty Organization (NATO) published satellite photos of Russian military forces on Russia’s border with Ukraine, and Russian President Vladimir Putin announced his plan to curtail gas sales to Ukraine. In addition to these two conflicts, pro-Russian insurgent groups have been gaining momentum in areas of Ukraine with high ethnic Russian populations.

The satellite photos, taken between March 22 and April 2, provide some of the first documentary evidence that Russia could be positioning its military to attack Ukraine. The photos show fighter jets and tanks in addition to 40,000 Russian troops stationed at the border. A satellite image of Belgorod, a Russian city 25 miles from Ukraine, revealed more than 20 Russian military helicopters. The photos were taken by DigitalGlobe, a Colorado-based commercial satellite imaging company that has contracts with the U.S. government.

Although Russian officials have accused the West of exaggerating Russia’s military presence, President Obama and other Western leaders have demanded that Putin withdraw forces contiguous to Ukraine. Gen. Philip M. Breedlove, a top NATO commander, said Russian forces would only need 12 hours notice to launch an attack.

In response, the Kremlin asserts that NATO interfering with Russian forces stationed in Russia would violate international agreements. Sergey V. Lavrov, Russian foreign minister, said that if NATO breaches these contracts, it would be “to satisfy absolutely groundless fears, phobias and ambitions of a minority of its country members.”

Also on Thursday, President Putin wrote a letter to European leaders addressing the possibility that Russia will require Ukraine to pay for gas a month in advance. In this letter, Putin stated, “To a large extent, the crisis in Ukraine’s economy has been precipitated by the unbalanced trade with the E.U. member states, and this, in turn, has had a sharply negative impact on Ukraine’s fulfillment of its contractual obligations to pay for deliveries of natural gas supplied by Russia.”

According to the New York Times, Europe receives about 13 percent of its natural gas from pipelines running through Ukraine. Russia meets a total of 30 percent of Europe’s demand for natural gas.

Putin also restated his threat of reducing gas sales to Ukraine. Gazprom, a Russian energy company, says Ukraine owes $2.2 billion in energy bills and will now nearly double gas prices for sales to Ukraine. This price hike is in response to the faltering Ukrainian economy, which began to fail under the mismanagement of former President Viktor Yanukovich and has continued to worsen since he was ousted by violent protests in February.

On Friday, Ukraine turned to other European nations for help. It now plans to receive gas from French energy company GDF Suez and Germany’s RWE, but no contracts have been signed.

Ukrainian Energy Minister Yuri Prodan told parliament that the EU would stand with the Ukraine if Russia decides to cutback energy supplies. This ensures that Russia cannot bypass Ukraine by siphoning gas through alternative pipelines. Prodan said, “Ukraine cannot pay such a political, uneconomic price, so now we are negotiating with the European Union about reverse deliveries into Ukraine.”

Ukraine accused Russia of denying gas as a punishment for forging stronger relationships with the E.U., and the U.S. says Russia is using energy as a “tool of coercion.” On April 11, Reuters calls the conflict, “the worst East-West crisis since the end of the Cold War.”

On April 13, the Ukrainian government announced it was dispatching troops to deal with the pro-Russian insurgency, despite warning from Russia that Russia would use military force to protect ethnic Russians in Ukraine. Kiev turned to military force in lieu of police forces because police have been unable and unwilling to fight Russian gunmen and loyalists. American news sources have filmed the inside of pro-Russian insurgent forts, which are armed with bricks, Molotov cocktails, and other makeshift weapons.

Oleksandr Turchynov, current president of Ukraine, accused Russia of causing the unrest and offered amnesty to those who have surrendered their weapons by Monday morning.

Putin’s letter to the EU:http://en.itar-tass.com/russia/727287

ABC News video of Pro-Russia insurgent fortress in Ukraine:http://abcnews.go.com/video/embed?id=23278506

(Sources: NYTimes, BBC, Reuters, ABC News, CNN)