If Russia seized Kyiv, it's security service had 2 pro-Russian governments ready

The Washington Post wrote about this. 

The publication reports that the former Ukrainian president Viktor Yanukovych, who fled to Russia in 2014, and the oligarch Viktor Medvedchuk were among the main allies of the FSB.

"Yanukovych was at the center of a group that gathered in Belarus in early March, presumably to invade and take back power. A second group, which included former members of Yanukovych's party, gathered in territory in southern Ukraine that was seized by Russian forces at the start of the war", it is noted. 

Journalists, based on the conducted research, report that an underground branch of the Russian security service assured officials in Moscow that the government of Ukraine would quickly fall.

"Despite the great attention paid to Ukraine, according to representatives of Western intelligence, the FSB either failed to understand how fiercely Ukraine would resist, or understood, but could not convey such inconvenient information to Russian President Vladimir Putin", the publication reported. 

It is noted that the FSB officers were so confident that they would seize power in Kyiv that they spent the last days before the war to arrange housing in the capital. It is added that despite repeated failures, the heads of the FSB remain in their positions.

"US and other officials have said they see no evidence that Putin has purged the top of Russia's spy services or held senior officials accountable for miscalculations. Instead, FSB director Oleksandr Bortnikov and the head of its Ukrainian office, Serhii Beseda, remain in their posts, overseeing aspects of military actions", the publication wrote. 

The Washington Post's months-long investigation draws on a range of classified materials, including intercepted communications involving Russian intelligence operatives, as well as detailed interviews with Ukrainian, American, and European officials.