The following analysis is sourced from publicly-available reporting by journalists embedded with the Russian military and the forces of the Donetsk People’s Republic, as well as Russian Ministry of Defense briefings and statements made by the Ukrainian side.
Within the first week of the Russian operation getting underway, it was clear to most that many of the assumptions that had been made were flawed and/or misplaced. First and foremost, Moscow had opted not to employ its forces according to standard doctrine, opting instead to take a light approach, which appeared to be born from a concerted effort to minimize civilian casualties and harm to civilian infrastructure that itself was derived from a fundamental misunderstanding of the reality of the situation on the ground in Ukraine.
The reported purging of 150 officers from the 5th Department of the Russian Federal Security Service (FSB), responsible for operations in the so-called ‘near abroad’ (which includes Ukraine), along with the arrest of Sergei Beseda, the former head of the department, suggests that Russia had suffered a failure of intelligence the likes of which has not been seen since the Israeli failure to predict the Egyptian crossing of the Suez Canal during the Yom Kippur War of October 1973.
While the Russian government has remained characteristically tight-lipped about any possible shortcomings regarding the work of the 5th Department prior to the start of the military operation, the statements by Russian leadership suggesting that the Ukrainian military might remain in its barracks and that civilian leadership would not interfere with Russia military operations suggest that these assumptions were made using intelligence provided by the 5th Department. That such assumptions, if indeed they were made, proved to be so fundamentally off target, when combined with the preparedness of the Ukrainian military to engage the initial columns of Russian forces, suggests that the work of the 5th Department had been disrupted by Ukrainian security services, who took control of Russian human networks and fed false reports back to the Russian leadership.