LONDON, Sept 21 (Reuters) - President Vladimir Putin on Wednesday ordered Russia's first mobilization since World War Two and backed a plan to annex swathes of Ukraine, warning the West he was not bluffing when he said he'd be ready to use nuclear weapons to defend Russia.
In the biggest escalation of the Ukraine war since Moscow's Feb. 24 invasion, Putin explicitly raised the spectre of a nuclear conflict, approved a plan to annex a chunk of Ukraine the size of Hungary, and called up 300,000 reservists.
"If the territorial integrity of our country is threatened, we will without doubt use all available means to protect Russia and our people - this is not a bluff," Putin said in a televised address to the nation.
Citing NATO expansion towards Russia's borders, Putin said the West was plotting to destroy his country, engaging in "nuclear blackmail" by allegedly discussing the potential use of nuclear weapons against Moscow, and accused the United States, the European Union and Britain of encouraging Ukraine to push military operations into Russia itself.
"If the territorial integrity of our country is threatened, we will without doubt use all available means to protect Russia and our people - this is not a bluff," Putin said in a televised address to the nation.
Citing NATO expansion towards Russia's borders, Putin said the West was plotting to destroy his country, engaging in "nuclear blackmail" by allegedly discussing the potential use of nuclear weapons against Moscow, and accused the United States, the European Union and Britain of encouraging Ukraine to push military operations into Russia itself.
"In its aggressive anti-Russian policy, the West has crossed every line," Putin said. "This is not a bluff. And those who try to blackmail us with nuclear weapons should know that the weathervane can turn and point towards them."
The address, which followed a critical Russian battlefield defeat in northeastern Ukraine, fueled speculation about the course of the war, the 69-year-old Kremlin chief's own future, and showed Putin was doubling down on what he calls his "special military operation" in Ukraine.
In essence, Putin is betting that by increasing the risk of a direct confrontation between the U.S.-led NATO military alliance and Russia -- a step towards World War Three -- the West will blink over its support for Ukraine, something it has shown no sign of doing so far.
Putin's war in Ukraine has killed tens of thousands, unleashed an inflationary wave through the global economy and triggered the worst confrontation with the West since the 1962 Cuban Missile Crisis, when many feared nuclear war imminent.
MOBILISATION Putin signed a decree on partially mobilizing Russia's reserves, arguing that Russian soldiers were effectively facing the full force of the "collective West" which has been supplying Kyiv's forces with advanced weapons, training and intelligence.
Speaking shortly after Putin, Defense Minister Sergei Shoigu said that Russia would draft some 300,000 additional personnel out of some 25 million potential fighters at Moscow's disposal.
The mobilization, the first since the Soviet Union battled Nazi Germany in World War Two, begins immediately.
Such a move is risky for Putin, who has so far tried to preserve a semblance of peace in the capital and other major cities where support for the war is lower than in the provinces.
Ever since Putin was handed the nuclear briefcase by Boris Yeltsin on the last day of 1999, his overriding priority has been to restore at least some of the great power status which Moscow lost when the Soviet Union collapsed in 1991.
Putin has repeatedly railed against the United States for driving NATO's eastward expansion, especially its courting of ex-Soviet republics such as Ukraine and Georgia which Russia regards as part of its own sphere of influence, an idea both nations reject.
Putin said that top government officials in several unnamed "leading" NATO countries had spoken of potentially using nuclear weapons against Russia.
He also accused the West of risking "nuclear catastrophe," by allowing Ukraine to shell the Zaporizhzhia nuclear power plant which is under Russian control, something Kyiv has denied.
ANNEXATION
Putin gave his explicit support to referendums that will be held in coming days in swathes of Ukraine controlled by Russian troops -- the first step to formal annexation of a chunk of Ukraine the size of Hungary.
The self-styled Donetsk (DPR) and the Luhansk People's Republics (LPR), which Putin recognized as independent just before the invasion, and Russian-installed officials in the Kherson and Zaporizhzhia regions have asked for votes.
"We will support the decision on their future, which will be made by the majority of residents in the Donetsk and Luhansk People's Republics, Zaporizhzhia and Kherson," Putin said.
"We cannot, have no moral right to hand over people close to us to the executioners, we cannot but respond to their sincere desire to determine their own fate."
That paves the way for the formal annexation of about 15% of Ukrainian territory.
The West and Ukraine have condemned the referendum plan as an illegal sham and vowed never to accept its results. French President Emmanuel Macron said the plans were "a parody." Kyiv has denied persecuting ethnic Russians or Russian-speakers.
But by formally annexing Ukrainian territories, Putin is giving himself the potential pretext to use nuclear weapons from Russia's arsenal, the largest in the world.
Russia's nuclear doctrine allows the use of such weapons if weapons of mass destruction are used against it or if the Russian state faces an existential threat from conventional weapons.
"It is in our historical tradition, in the fate of our people, to stop those striving for world domination, who threaten the dismemberment and enslavement of our Motherland, our Fatherland," Putin said.
"We will do it now, and it will be so," said Putin. "I believe in your support.
"UPDATE:
Speaking to the United Nations General Assembly, President Joe Biden on Wednesday cast the defining conflict facing global leaders as a duel between democracy and autocracy, directly responding to new threats from Russian President Vladimir Putin to escalate the war in Ukraine.
The speech is Biden's first at the forum since Russia's invasion, offering him the opportunity to condemn the Kremlin in front of an audience of fellow heads of state.
Biden opened his remarks with a strong rebuke of Putin after he earlier Wednesday ordered a partial mobilization of reservists in Russia and raised the specter of using nuclear weapons after a retreat in the northeastern Kharkiv region.
"Let us speak plainly, a permanent member of the United Nations Security Council invaded its neighbor, attempted to erase the sovereign state from the map," Biden said. "Russia has shamelessly violated the core tenants of the United Nations Charter."
"Just today, President Putin has made overt nuclear threats against Europe and reckless disregard of the responsibilities of a nonproliferation regime," Biden continued. "Now, Russia is calling, calling up more soldiers to join the fight and the Kremlin is organizing a sham referendum to try to annex parts of Ukraine, an extremely significant violation of the U.N. Charter. The world should see these outrageous acts for what they are."