Sen. Lindsey Graham (R-SC) called out entrepreneur Elon Musk on social media Wednesday afternoon over his remarks on Russia’s invasion of Ukraine, and he quickly received a response from the multi-company executive. Graham also took an apparent shot at Tesla over Musk’s remarks, suggesting that lawmakers should revisit tax credits for electric vehicles.

Graham’s remarks come after Musk proposed earlier in the week that the will of the people who live in Donbas and Crimea should decide whether they stay part of Ukraine or whether they join Russia.

“It is very positive that somebody like Elon Musk is looking for a peaceful way out of this situation,” Kremlin propagandist Dmitry Peskov responded. “Compared to many professional diplomats, Musk is still searching for ways to achieve peace. And achieving peace without fulfilling Russia’s conditions is absolutely impossible.”

Graham responded to Musk’s proposal in a lengthy Twitter thread, saying that Musk needed to “understand the facts of the Russian invasion of Ukraine.”

“Suggesting we end the Russian invasion by simply giving Russia parts of Ukraine – after all the suffering – is dumb,” Graham said.  “In 1994, through the Budapest Memorandum, Ukraine gave up its nuclear weapons arsenal — the third largest in the world — in return for assurances their territorial integrity would be protected. It was an agreement signed by Russia that included protecting Crimea and the Donbas as part of Ukraine. If you want peace in Ukraine — which we ALL do — simply demand Russian honor the boundaries they agreed to in 1994 and withdraw their forces.”

“To do otherwise is to legitimize a bait and switch by Russia and a signal to other bad actors to take what you want – by force! If Elon Musk and others want the world to continue to be in chaos, then by all means capitulate to Putin and reward his aggression,” Graham continued. “While we’re at it, maybe the Congress should revisit the electric vehicle tax credit boondoggle. It is where the credit is now solely benefiting electric vehicle manufacturers who have increased prices equal to the tax credit! It could be a good way to help save money by applying those funds to assisting Ukrainians in defending their homeland!”

Musk responded with a map showing how people voted in parliamentarian elections a decade ago and used it to suggest that some those who voted for the pro-Russia party would have wanted to break off from Ukraine.

“Assuming you believe that the will of the people matters, we should, in any given conflict region, support the will of those who live there,” Musk responded. “Most of Ukraine unequivocally wants to be part of Ukraine, but some eastern portions have Russian majorities and prefer Russia.”

Musk also responded to Graham making a slight threat at Tesla with his tweet about lawmakers potentially needing to revisit tax credits for electric vehicles.

“First of all, Tesla hasn’t had that consumer tax credit for years & we didn’t ask for this one – GM & Ford did,” Musk fired back.