Russia vowed yesterday to adopt a strengthened military doctrine over Nato's plans to establish a rapid-response team that could ward off the Kremlin's expansion into Ukraine and its feared push further west.
Moscow's surprise announcement added a new and threatening new layer of tensions ahead of Nato's two-day summit that starts tomorrow in Wales and will see Ukraine's beleaguered leader Petro Poroshenko personally lobby US President Barack Obama for military help.
The Ukrainian president's appeal for European assistance in the face of Russia's alleged dispatch of crack troops into the separatist east of his ex-Soviet country was effectively cast aside by EU leaders meeting over the weekend in Brussels.
But Nato chief Anders Fogh Rasmussen said in Brussels that the 28-nation alliance would endorse the establishment of a force of "several thousand troops" that could be deployed within "very few days" to meet any perceived Russian military movements in eastern Europe.
The New York Times reported the rapid-response unit would be supported by new Nato members such as Poland that were once Soviet satellites but now view Russian President Vladimir Putin with fear and mistrust.
Moscow's answer to Nato's intentions was instant and furious.
The Russian national security council's deputy secretary, Mikhail Popov, said the mooted Western defence plan was "evidence of the desire of US and Nato leaders to continue their policy of aggravating tensions with Russia".
Popov added that Russia's 2010 military doctrine - a document that already permits the use of nuclear weapons should national security be considered in grave danger - would sharpen its focus on overcoming Nato and its new European missile defence system.
"I have no doubt that the question of the approach of Nato members' military infrastructure to our border, including by an expansion of the bloc, will remain one of the foreign military threats to Russia," he said.
Defence Minister Sergei Shoigu said in separate comments that Russia's armed forces would be given added muscle with the deployment of 230 new military helicopters and jets by the end of the year.
Poroshenko convened his own national security and defence council late on Monday to figure out how military leaders could halt their forces' recent retreat from eastern territories.
"The situation is difficult but the Ukrainian fighting spirit is stronger than that of the occupants," Poroshenko said in reference to more than 1,000 Russian soldiers that Nato believes the Kremlin pushed across the Ukrainian border in recent days.
The press offices of Ukraine's self-declared "anti-terrorist operation" reported "ferocious battles" across the rebel-held eastern industrial regions of Luhansk and Donetsk.
It accused "terrorists dressed in Russian army uniforms of attacking medical columns of the Ukrainian armed forces that were being used to transport wounded soldiers and were clearly marked".
Moscow on Monday again denied either sending or planning to deploy troops to eastern Ukraine to help insurgents open a corridor along the Sea of Azov between the Russian border and the Crimean peninsula which the Kremlin annexed in March.
But top separatist commanders have admitted that some off-duty and vacationing Russian soldiers had already joined their ranks.
The ominous sense of Moscow and the West digging in for a cold war-style stand-off with unimaginable consequences for global security prompted UN secretary general Ban Ki-moon to caution all sides that "there is no military solution" to the crisis.