Since Russia's entire media and leadership has genocidally declared Ukraine to not exist, there's nothing to negotiate with an invader whose leader is an indicted war criminal.
"Russia has 1000 years of institutional knowledge of war" --Why Mr. Dunn keeps writing that Russia has existed and been fighting wars for 1000 years when Moscow was a bog and forest until the 14th century? The idea that the Viking warlord Russians call Vladimir (Voldemar) was Russian at all is Russian ethnonationalist propaganda that he keeps repeating. Watch Tim Snyder's Yale course The Making of Modern Ukraine to cease being a recidivist repeater of Russia's weaponization of history. Otherwise, the war that never stops is his relentlessly recidivist war on facts through mindless repetition of Russian propaganda.
Repeat after me: Russia did not exist 1000 years ago.
"expense of building Ukraine"--Math is beyond Mr. Dunn. The countries supporting Ukraine have $70tn in GDP. $1.3tn rebuilding cost = less than 2% of that GDP.
"If you want to stop Russia from making war, you have to stop making war against Russians."--Russia has made war on Ukraine for three centuries. The correlation between Russian aggression and western behavior is a very simple number: zero. This line is classic projection and Russian collective narcissist victimhood.
"Sanctions are only making them stronger"--So math illiterate customer service rep Mr. Dunn knows more about the Russian economy than Oleg Deripaska, who just said that by the end of 2023 Russia will exhaust its forex reserves. Last month to finance the war (pardon, SMO), Russia drew down $8bn from its sovereign wealth fund of $148bn. March's drawdown will certainly be much higher. Why" They're selling oil to India and China at below break even of $54/barrel not including the $12/barrel transshipment and at sea small to super tanker bunkering cost. They can't get reinsurance on their oil and LNG shipments because of the price cap.
"honestly negotiate for peace"--Lavrov the Liar has said multiple times that the premise for negotiations is Ukraine accepting Russia's annexations of the four regions of Kherson (half-evacuated by Russia in November), Zaporizhia, Luhansk and Donetsk. Continued occupation of those regions and Crimea and the naval base at Sebastopol by Russia would mean Ukraine never becomes a viable state. Nobody negotiates their own demise.