16:15 - Source: CNN
'An invented history': Experts unpack Putin's Ukraine fixation
CNN  — 

Russian President Vladimir Putin has now assembled 70% of the military personnel and weapons on Ukraine’s borders he would need for a full-scale invasion of the country, according to two US officials familiar with the latest estimates.

The figure is an estimate based on the latest intelligence assessments, but officials would not specify the intelligence they had or how they developed their assessments, citing the sensitivity of how they collect the information. The assessment represents the continuing significant buildup of Russian forces on Ukraine’s borders, but it’s unclear how long it would take Putin to ramp up further, or whether the Russian president would need full capabilities in order to invade.

The human cost could be dire: Some assessments calculate civilian casualties in Ukraine could run into the tens of thousands with up to five million refugees.

US officials publicly and privately still say they do not know if Putin has made a final decision on any type of military action, but behind the scenes, President Joe Biden’s national security and intelligence teams are calculating various scenarios and the potential outcomes.

In closed-door, classified briefings to Congress as well as in public press conferences, US officials are trying to draw a picture of potentially dire outcomes and the risk Putin poses. There is a strong desire among US officials to explain to the American public why the fate of Ukraine could usher in an era of security and economic destabilization which could ripple across the globe.

Russia continues to add forces to the region almost daily, according to US estimates, and could soon have enough to begin an operation. Given all Putin has moved, plus his public rhetoric on Ukraine and NATO, US officials widely believe he could soon make a decision, and it may be more likely than not he will move ahead.

Officials stress constantly the intelligence they have is leading them to make these estimates, but they are just estimates. But some are chilling.

For example, if Putin were to unleash his full land and air military might on the Ukrainian capital of Kyiv, the city might fall in 48 hours. They also calculate Putin could decide for a multipronged operation, sending in forces from several directions across Ukraine to quickly fracture the ability of Ukraine’s military to fight as a cohesive force; a Russian strategy that is a classic military move.

The Pentagon has openly hinted at the status of potential Russian invasion forces. “Mr. Putin continues to add forces, combined arms, offensive capabilities,” Pentagon press secretary John Kirby said earlier this week. “He has shown no signs of being interested or willing to deescalate the tensions.” Putin has not just infantry and missile forces, but hundreds of fighter and bomber aircraft as well as attack helicopters at his disposal.

“There’s a potential they could launch on very little warning,” Chairman of the Joint Chiefs of Staff Gen. Mark Milley warned at a news conference January 28, offering a brutal assessment.

“Given the type of forces that are arrayed … if that was unleashed on Ukraine, it would be significant, very significant, and it would result in a significant amount of casualties,” Milley said. “You can imagine what that might look like in dense urban areas, along roads, and so on and so forth. It would be horrific. It would be terrible.”

Based on publicly available weather calculations, the optimal time for a Russian invasion would be while there is a hard ground freeze, so heavy equipment can readily move. US officials have said Putin would understand he needs to move by the end of March.