Who was doing that? You are setting up a straw man. Supporting peaceful democratic reforms is not plotting to overthrow the government.
Peaceful democratic reforms? You must be kidding, of course. Using Peaceful Molotov cocktails and Peacefully threatening to storm parliament using Peaceful neo-Nazis and hard line nationalist nut cases?
Nuland was directing the US ambassador to get who she wanted to run Ukraine. Nuland admitted recently in a speech that the US had spent 5 Billion dollars since 1992 to influence 'democracy' in the Ukraine. Paying off agitators, corrupt officials and brainwashing naïve people through paid off NGO's and social media into causing an uprising IS plotting to overthrow a government, and an fairly elected government at that. Typical CIA involvement. Like they did in Ecuador in the '60's, Iran in 1954, Vietnam in 1962, Chile in the '70's and most of the banana republics in Central America. Of course, they just use brute force against small countries nowadays, like Grenada, Panama, Libya, Iraq and Afghanistan.
Get a hold of the still banned in-the-US 'CIA Diaries', written by the defector Philip Agee. He shows how it's all done.
The problem now, is that 20,000 people demonstrating might look impressive as seen through the nightly news, but was not democratic. The Eastern and Southern residents of Ukraine never supported this uprising and coup, and now they are showing their resistance. The Ukrainian government can't mount an offensive against secessionist regions if half of their commanders defect and half of the soldiers refuse to fight.
The US/EU miscalculated badly if they thought that the Russians would be forced to abandon their bases in Crimea simply by changing the government. Putin doesn't care if Russia is barred from the G8 or whatever. The strategic importance of a non-NATO Ukraine and the Black Sea Fleet staying in Sevastopol is far more important to him. Meanwhile, because of foreign meddling, Ukraine is in more desperate economic trouble than ever before. If the IMF ever get involved, it will mean an unprecedented period of austerity, much worse than Greece, the likes nobody has seen before.