Russian President Vladimir Putin accused the West on Friday of colonial arrogance and trying to crush his country with "stupid" sanctions that amounted to an economic "blitzkrieg".
Addressing the St Petersburg International Economic Forum, a showcase event being held this year with almost no Western participation, he returned time and time again to the theme of Russia's sovereignty and strength in the face of what he presented as Western hostility:
"We are strong people and can cope with any challenge. Like our ancestors, we will solve any problem, the entire thousand-year history of our country speaks of this."
Putin drew applause from the hall when he reaffirmed his determination to continue the "special military operation" in Ukraine that has unleashed what he said was an "unprecedented" barrage of Western economic sanctions.
He said the main aim of the incursion was to defend "our" people in the largely Russian-speaking Donbas region of eastern Ukraine - a justification that Kyiv and the West dismiss as a baseless pretext for a campaign that has already led to the occupation of parts of southern Ukraine far beyond the Donbas.
In a speech that lasted well over an hour, Putin said the Russian soldiers in the Donbas were also fighting to defend Russia's own "rights to secure development".
"The West has fundamentally refused to fulfil its earlier obligations, it turned out to be simply impossible to reach any new agreements with it," Putin said.
"In the current situation, against a backdrop of increasing risks for us and threats, Russia's decision to conduct a special military operation was forced - difficult, of course, but forced and necessary."
He called the campaign the action of a "sovereign country that has the right to defend its security", and accused the West not only of whipping up anti-Russian feeling but also of "active military appropriation of Ukrainian territory".
Putin said the United States considered itself "God's emissary on Earth", and that Western sanctions were founded on a false premise that Russia had no economic sovereignty.
Washington and its allies were trying to "change the course of history", he said.
Shortly before Putin was due to begin speaking, the Kremlin announced that a "denial of service" cyber attack had disabled the accreditation and admission systems of the conference, forcing him to delay the scheduled start of his speech by an hour.
Putin said the EU could lose more than $400 billion this year due to the sanctions, which he said would rebound on those who had imposed them.
He dismissed suggestions that Russia was responsible for a sharp rise in global prices of basic foodstuffs with the phrase that a failure to export five or six tonnes of Ukrainian wheat and six or seven tonnes of corn "doesn't change the weather".
He said Russia was ready to guarantee the transit of ships exporting Ukrainian grain across the Black Sea, but that Ukraine had five or six other ways to export its grain, through Belarus, Poland or Romania.
Ukraine has been using alternative road, rail and river routes to try to get around the closure notably of Odesa, its main deep-sea port, for fear of Russian attack.
But the other routes are much more cumbersome and their capacity is at best a third of the more than 6 million tonnes a month of grain and oilseeds that were shipped from Odesa in the past.