Russian News Agency Interfax is quoting a source in the Ukrainian Defense Ministry, that the Russian Black Sea Fleet demands Ukrainian forces in Crimea stand down by 0300 GMT Tuesday, or they will risk a direct assault on their bases.
The statement hasn’t been confirmed by either side, and I am skeptical. I don’t think Russian forces need to escalate further at this point – they already control Crimea, and if the standoff turns into a shooting war the result is going to spin out of control very fast. At this point the Russians can continue to claim they are acting to protect the safety of ethnic Russians in Crimea, but that fig leaf will be torn away if Russian forces become the aggressors. Though news sources are reporting the arrival of reinforcements over the weekend, I also question whether Russia has enough troops and equipment on the ground to guarantee a successful assault through overwhelming force.