The current confrontation between Russia and the West over Ukraine is unparalleled in history and a mistake could lead to catastrophe, a senior Russian diplomat said on Thursday when asked about comparisons to the 1962 Cuban Missile Crisis.
The 2-1/2-year-old Ukraine war, the biggest land war in Europe since World War Two, has triggered a major confrontation between Russia and the West, and Russian officials say it is now entering its most dangerous phase to date.
Russian diplomats have previously invoked comparisons to the 1962 crisis when the Cold War superpowers are considered to have come closest to intentional nuclear war after Moscow secretly put missiles on Cuba.
But Deputy Foreign Minister Sergei Ryabkov told reporters on Thursday: "What is happening has no analogues in the past."
Ryabkov, who oversees arms control and relations with North America, told reporters in Moscow that the danger of an armed clash between the nuclear powers should not be underestimated.
"We are moving through unexplored military and political territory," he said.
Ryabkov said that a mistake at the current juncture could usher in disaster, but questioned whether or not those in the West were able to "sensibly assess the consequences of their course".
Russia has been warning the United States and its allies for weeks that if they give permission to Ukraine to strike deep into Russian territory with Western-supplied missiles, then Moscow will consider it a major escalation.
Ukrainian President Volodymyr Zelenskyy has been urging Kyiv's allies for months to let Ukraine fire Western missiles, including long-range US ATACMS, deep into Russia to limit Moscow's ability to launch attacks.
President Vladimir Putin said on 12 September that Western approval for such a step would mean "the direct involvement of NATO countries, the United States and European countries in the war in Ukraine".
The Kremlin chief has changed Russia's nuclear doctrine to give Russia a slightly lower threshold for using such weapons in response to the situation.
Zelenskyy has urged the West to cross and disregard Russia's so-called "red lines", and some Western allies have urged the United States to do just that. Russia, the world's largest nuclear power, says that is folly.