KYIV, Ukraine — While the Russian military is not yet capable of mounting a total invasion of Ukraine, portions of its army have reached full combat strength and appear to be in the final stages of readiness for military action should the Kremlin order it, according to an assessment by the Ukrainian military’s high command.
Of particular concern to Ukrainian officials is the Crimean Peninsula, which Russia seized from Ukraine in 2014. In the last two weeks, Russia has deployed an additional 10,000 troops to the region, including infantry and airborne forces; more ominously, it has put some commands on the highest level of readiness, according to the military’s assessment.
Along with recent efforts to strengthen forces near two Kremlin-backed separatist enclaves in Ukraine, the deployments mean that Russia could soon be fully prepared to begin military actions along about 800 miles of Ukraine’s eastern and southern borders, according to the assessment.
The assessment was described in general terms by a senior Ukrainian military official who spoke on condition of anonymity to disclose confidential intelligence findings. It broadly aligns with newly released satellite images showing a significant military buildup in Crimea over the last few weeks.
But it is not just Crimea. Along much of Ukraine’s border, analysts are seeing what they describe as a near textbook example of a modern military making final preparations for war. They cited the arrival of logistical infrastructure like hospital and communications units, elements of electronic warfare meant for disrupting enemy communications, air power and additional troops to man equipment that was deployed earlier.
“What unnerves me is how methodically they’re going through this,” said Dara Massicot, a senior policy researcher at the RAND Corporation. “It’s by the book. You know what’s coming next and it shows up.”
The Kremlin’s ultimate intention remained unclear, the Ukrainian official said, echoing the determination of American officials who say that President Vladimir V. Putin of Russia has yet to decide whether to attack.
Russia has roughly 130,000 troops massed near Ukraine’s border, U.S. and Ukrainian officials say. The Kremlin has said repeatedly it has no plans to attack, and Mr. Putin — while claiming that the United States was trying to goad Russia into war — was less strident in his language in an appearance this week, leaving the door open for future diplomacy.
The Ukrainian military’s assessment of Russian capabilities diverges from one the Pentagon provided last week, which said that Moscow had deployed sufficient troops and military hardware to go far beyond a limited incursion into only the border regions. But it moved Ukraine’s military leadership closer to the American position.
And it painted a dire picture of Russian combat readiness in Crimea, an area that has drawn less attention; for months the focus has been on a Russian troop buildup in the east and, more recently, its moving of forces into Belarus on Ukraine’s northern border.
On top of the tens of thousands of troops already stationed in Crimea, Russia has recently deployed two additional battalion tactical groups — battle ready forces of up to 1,000 troops plus tanks, armor and artillery. This includes one group of airborne troops and another that arrived with 10 trains’ worth of equipment and armor, the senior Ukrainian official said.
Ukrainian military officials assess that additional forces are on the way, including a subdivision of national guard troops, which could be deployed to hold territory in the event of an invasion.
Moreover, several units deployed to Crimea have been put on the Russian military’s highest state of military readiness, the official said, including marine forces based near the Kerch Strait, which separates mainland Russia from Crimea, and at the headquarters of Russia’s Black Sea Fleet in Sevastopol. Troops in other locations have been put on the second highest level of alert, the official said.
Satellite images released by Maxar, a space technology company, this week confirm a buildup of forces in Crimea. They show the addition of numerous tent camps in areas close to military equipment, an indication that troops had arrived or were on the way.
The senior Ukrainian official said any incursion could start with localized action and that, if successful, could prompt the Russians to expand the conflict zone. “For now, they’re doing everything they can to panic us and panic the West,’’ the official said, calling it “a real game of poker.”
The Crimea troops are augmented by Russian naval forces deployed to the Black Sea and Sea of Azov, a small strategic body of water over which Ukrainian and Russian forces have clashed repeatedly in recent years. Last April, Russia dispatched its Caspian Flotilla to the waters around Ukraine for exercises and left behind several large landing craft.
Ukrainian officials are now watching the movements of six Russian landing vessels capable of deploying tanks and thousands of troops that Russia has sent from its Baltic and Northern Fleets for exercises in the Mediterranean for any signs that they may continue into the Black Sea.
“It’s a huge assault grouping,” Ihor Kabanenko, a retired admiral with the Ukrainian Navy, said. “We have not enough capabilities at sea to adequately respond to such a Russian deployment.”
Beyond Crimea, military analysts say it may only be a matter of weeks before the crescent of troops deployed along Ukraine’s northern, eastern and southern border is ready for action.
Until now, such forces might have looked menacingly large, but they lacked the supply lines and other logistical infrastructure needed to fight.
The satellite images showing row upon row of tanks that have appeared regularly in newspapers were most likely meant to send a message and force a conversation, said General Philip M. Breedlove, who was formerly the supreme allied commander of NATO.
Understand the Escalating Tensions Over Ukraine
Ominous warnings. Russia called the strike a destabilizing act that violated the cease-fire agreement, raising fears of a new intervention in Ukraine that could draw the United States and Europe into a new phase of the conflict.
The Kremlin’s position. President Vladimir V. Putin of Russia, who has increasingly portrayed NATO’s eastward expansion as an existential threat to his country, said that Moscow’s military buildup was a response to Ukraine’s deepening partnership with the alliance.
“You’ve seen the pictures of the trucks lined up,” Gen. Breedlove said. “That is not in tactical or offensive formation. That’s a formation for show.”
All that has started to change in recent weeks with the arrival of Iskandar-M cruise missiles, fighter jets and helicopters, according to satellite imagery, Ukrainian and western intelligence assessments and Russia’s own military announcements.
In some areas where Russia still does not have enough personnel to man equipment, more troops appear to be arriving daily, officials and analysts say. And there is still a question of whether the Russian military has been able to muster sufficient reserve forces for any prolonged military campaign.
In the coming weeks, Russia will likely conduct a series of military drills meant to test the preparedness of its forces, said Michael Kofman, the director of Russia studies at CNA, a research institute based in Arlington, Va. After that, the troops need only to get in their vehicles and head for the Ukraine border, he said.
What a military operation might look at this point is hotly debated.
In late January, Defense Secretary Lloyd J. Austin III and Gen. Mark A. Milley, the chairman of the Joint Chiefs of Staff, said that Russia had deployed enough forces to invade all of Ukraine, and suggested that fighting could even extend to the streets of Kyiv, the capital, something Mr. Kofman agrees with.
“The Russian military is positioning itself to be able to conduct a large scale military operation against Ukraine, and its force posture indicates that if given the order they’re going to conduct a multi-axis attack,” Mr. Kofman said.
Under Ukraine’s assessment, Russia would be unable to sustain an invasion across different points of attack for more than a week because of a lack of supplies including ammunition, food and fuel deployed to front line positions, nor does it have sufficient reserve forces.
In most areas there are enough forces available for smaller, localized assaults that could be used as a diversion from a main attack coming from the east or south where forces are stronger, according to the assessment.
For weeks, Ukraine’s president, Volodymyr Zelensky, has attempted to play down the severity of the Russian threat, though even he now appears to be growing more concerned.
“This is not going to be a war of Ukraine and Russia,” should diplomatic efforts still underway fail, Mr. Zelenksy said last week. “This is going to be a European war, a full-fledged war.”