White House national security adviser General H.R. McMaster told reporters last week that there was “no specific agenda” for the upcoming meeting between President Trump and Russian President Putin at the G20 summit in Hamburg, Germany. Trump will emphasize “whatever the president wants to talk about,” McMaster said.

Press reports indicate President Trump has tasked his staff to compile steps he could offer to Putin, presumably to demonstrate that nothing—neither investigations back home nor concern about the threat that Putin poses—will keep him from trying to strike a deal with his Russian counterpart. The media hasn’t always gotten the story right on how the Trump bureaucracy operates, but there’s plenty of reasons to suspect that the President himself is still keen to give dealmaking with Moscow a ago. After all, throughout the campaign last year and into his Presidency, Trump has consistently expressed his desire to find a way to get along with Russia and Putin.

So why shouldn’t the President give it a shot? The best way to answer that question is to ask a different one: Is it possible to work with the Putin regime? The answer to that question is decidedly “no”. A brief look at recent events ought to convince any open-minded individual that Russia simply can’t be a partner—and indeed has no desire to be one.

“Wouldn’t it be nice if we got along with Russia? Wouldn’t it be great if we and Russia got together to knock the hell out of ISIS?” President Trump has mused on numerous occasions. Well let’s not forget that when Russia intervened militarily in Syria in late Sept 2015, it did so not to battle ISIS but to prop up that country’s murderous Assad regime. And the vast majority of Russian strikes in Syria have been not on ISIS but on moderate opposition forces in Syria, including ones the United States has trained, and against civilians and humanitarian convoys. The risk of a clash between Russian and American planes over Syria is real, as we disagree over who is a terrorist versus who represents the moderate opposition. Deconflicting both Syria’s airspace and its battlefields is important, but we should have no illusion as to how much help Russia will be in the fight against ISIS. Indeed, the Trump Administration’s fight against ISIS is proceeding just fine without any help from Moscow, with the so-called Caliphate increasingly looking as if it’s on its last legs.

Need more evidence of Putin’s mercenary attitude towards terrorism? In Afghanistan, Russia has been actively supporting and arming the Taliban in its attacks on U.S. forces. And as General John Nicholson testified to the Senate earlier this year, that means Moscow has been knowingly aiding Al-Qaida, which uses the Taliban insurgency as a “medium” for its own operations.

Maybe Putin can help with North Korea? Not likely. Russia has nowhere near the influence over the murderous Kim regime in Pyongyang as China does. And where Moscow could conceivably be helpful on the margins, it has instead opted for the opposite tack. Case in point: A new ferry link between North Korea and Russia was opened for the first time, despite U.S. calls for countries to downgrade relations with Pyongyang over its nuclear and missile-testing programs.

How about Iran? Yes, Russia played a role in facilitating the 2015 nuclear deal, but it also sells Iran advanced missile defense systems and other technology and weapons and is working closely with Tehran to support the Assad regime in Syria. Tehran’s relationship with Moscow is not profoundly deep, and is plagued by mutual mistrust, but it also has a long history stretching back into the Cold War. Much like with Assad in Syria and with the Taliban in Afghanistan, Putin likes propping up regional U.S. opponents in order to maximize his leverage elsewhere.

As for cyber, Russian security services were responsible for the worst foreign interference in an American election in our history. These same people do the same thing in countries throughout Europe. Given that the Russians still firmly deny any and all responsibility for their behavior, what could we possibly expect to achieve through sitdowns with Moscow on cyber?

More broadly, Putin’s regime simply doesn’t abide by agreements it has signed or inherited. It has been violating arms control agreements by developing and testing missiles in violation of the INF treaty. It has never abided by the ceasefire deal following its invasion of Georgia in 2008. It has never complied with two Minsk ceasefire deals following its illegal annexation of Crimea in 2014 and ongoing invasion of and aggression against Ukraine in that country’s east. It has violated the Budapest memorandum of 1994, the Friendship Treaty with Ukraine in 1997, and the principles of sovereignty and territorial integrity. It didn’t respect any ceasefire deals in Syria. And it grossly abuses the human rights of its own people despite being a member of the Organization for Security and Cooperation in Europe and the Council of Europe as well as a signatory to the Universal Declaration of Human Rights.

Putin, in other words, is a wholly untrustworthy interlocutor. His regime is thoroughly corrupt and authoritarian and poses a threat to its own people, its neighbors, and the West.

Every single Administration since the Cold War has thought it could do better than the previous one when it comes to relations with Russia. Every single Administration has come away disappointed. Maybe this endless cycle of dashed hopes just needs to play out once again, but in today’s increasingly dangerous world, it would be much better if the Trump Administration would forego the “learning curve” period. By the end of his term, President Obama’s spine had started to stiffen in the face of repeated Russian provocations. President Trump would do well to pick up where his predecessor left off:

• Ramp up, not simply maintain, existing sanctions.
• Ramp up support for reform-minded forces inside Russia.
• Bolster Russia’s neighbor: provide lethal assistance to Ukraine to help it defend itself against Russian aggression, and beef up the defense of NATO allies along Russia’s borders.
• Work to prevent the import of corruption from Russia, which infiltrates and infects our own systems.
• Support diversification of energy supplies in Europe and unleash the export of American energy.

Trump should avoid personalizing relations with the Russian leader or appearing over-eager for improved ties with Moscow. He should speak out about Russia’s deteriorating human rights situation and reject any moral equivalence between Putin’s Russia and the United States. He should not consign Russia’s neighbors to a Russian sphere of influence through any grand deals, accommodation, trade-offs or general neglect.

The sad truth is that Russia simply needs to viscerally understand that its probing, destabilizing behavior is hitting hard limits and actively backfiring. Dialogue simply won’t work with Putin’s murderous, treacherous, kleptocratic regime.

The next time President Trump asks, “Wouldn’t it be nice if we and Russia got along?” answer with the following: How many more Russian liberal activists need to be killed or poisoned? How many more countries does Putin need to invade? How many more Ukrainians need to die? How many more civilians need to be killed in Syria? And how many more elections does he need to interfere in—before we understand the existential threat the Putin regime represents?