Ukraine has avoided bankruptcy and social collapse thanks to a "historic" deal with Russia for Moscow to buy $15 billion of Ukrainian bonds and slash gas prices, its prime minister said Wednesday. "What would have awaited Ukraine (without the deal)? The answer is clear -- bankruptcy and social collapse," Prime Minister Mykola Azarov told parliament, hailing the "historic" deal and warning that the government would now "not allow anyone to destabilise" the situation in the country.