In physics, Newton’s third law tells us that to every action there is an opposite and equal reaction. In diplomacy, however, sometimes reactions are disproportionate, or even irrational.

The art of diplomacy is trying to read the mind of one’s adversary and predict what may be his or her response. In times of war, though, rashness often replaces rationality and calls for justice drown out a full appreciation for the enemy’s threats.

Advocates of a never-retreating Hegelian march to freedom everywhere often admit they don’t care what our enemies say or promise to do. But refusing to understand or at least acknowledge an adversary’s demands is and always will be a recipe for perpetual war.

While there is no justification for Putin’s invasion of Ukraine, it cannot be argued that he didn’t telegraph that it would happen.

When Western intelligence agencies worked with Ukrainian Maidan protesters to topple the Russian-backed leader of Ukraine in 2014, Putin reacted by taking Crimea. When the Biden administration signed an accord with Ukraine reiterating an invitation for Ukraine to join NATO last fall, Putin responded with a massive invasion of Ukraine. Of course, nothing justifies the invasion, but it is an error to argue that it was not predictable.

In the end, history will likely judge Putin’s decision to invade as a complete failure. It has united Europe, increased the continent’s resolve to become independent of Russian oil and gas, and ultimately encouraged Sweden and Finland to reject neutrality and move to join NATO.

Putin’s invasion of Ukraine completely changed public opinion in Sweden and Finland about joining NATO. Sweden’s over-100-year policy of neutrality was swiftly discarded.

Will Sweden’s and Finland’s ascension to NATO be beneficial to America? Will their joining cause more or less war?

Well, for every action there is a reaction. What does our adversary say?

Putin’s immediate response to the development was that Russia “does not have a problem” with Sweden or Finland applying for NATO membership, but that “the expansion of military infrastructure onto this territory will of course give rise to our reaction in response.”

So, there you have it. Russia likely will tolerate Sweden and Finland in NATO but likely will not tolerate certain weapon systems in Finland. (Does anyone remember U.S. missiles in Turkey and Russia’s response placing Russian missiles in Cuba?)

If having Sweden and Finland in NATO does not lead to conflict, it will support the argument that NATO is a deterrent to war. But, if having Sweden and Finland in NATO leads to conflict, as did the agitation for Ukraine in NATO, will NATO expansionists admit the provocation? 

It is not just conventional war that is risked with such provocations. What if such actions lead to overreactions, such as nuclear war? 

Advocates of NATO expansion say we can’t be held hostage to Russia’s threats. Perhaps. But if a country announces they will do X if you do Y, shouldn’t someone, at least, contemplate the potential scenarios? 

The Russians have already announced that placing certain weapon systems in Finland is a red line. Whether the red line is justified is not the issue. The issue is, knowing your adversary’s position, is it worth the risk of pushing missiles into Finland?

The world has changed since Putin invaded Ukraine. Arguments that admitting Sweden and Finland to NATO could provoke Russia are less potent now, since Putin’s war shows he can be provoked by actions short of Ukraine’s actual admission to NATO.

Diplomats, though, should try to envision how the Ukraine war might end. One possible end would be, as Zelensky has stated, a neutral Ukraine not militarily aligned with either the West or the East. One possible bargaining chip for peace might be Sweden and Finland also remaining neutral and out of NATO. I doubt that will happen. I think that train has left the station.

But it is worth contemplating. Neutrality doesn’t have to be a weakness. Neutral nations can serve as intermediaries in conflict resolution. Often, our discussions with Iran use neutral Sweden as a conduit. When all nations are aligned, who will be the mediators?

The U.S. Senate will likely vote this summer on admitting Sweden and Finland to NATO. Prior to Putin’s invasion of Ukraine, I have been an automatic “no” on expanding NATO to Russia’s borders. I have seen such expansion as needless provocation. 

But Putin’s invasion of Ukraine has changed the world and a realistic view of foreign policy changes as the world does. In this new world, I am less adamant about preventing NATO’s expansion with Sweden and Finland.

In the coming days I will propose conditions to the treaty stating that Article 5 does not supersede the constitutional requirement that Congress declare war before engaging in hostilities, and that the U.S. will not bear any costs caused by the addition of Sweden and Finland to NATO.

I still sympathize with the view of Doug Bandow, who wrote here at The American Conservative: “Russia’s poor military performance demonstrates that, contra its pre-conflict reputation, Moscow could not conquer its many neighbors, let alone the entire continent, even if it desired to do so. The two countries’ desire to join appears to be an attempt to get an insurance policy at America’s expense, expanding still further Washington’s already lengthy list of defense dependents.” 

But Putin’s war on Ukraine has colored the situation and arguments against Sweden and Finland abandoning neutrality are less certain. Putin’s aggression has altered the playing field. Once-timid European countries are now rejecting Russia’s oil. Countries across Europe have shifted their views. 

It is, without question, more difficult to argue that NATO expansion is provocative when Putin is clearly already provoked. But the Russian invasion of Ukraine should make us all wake up to the stark realities of war between peers. In that light, we should tread with extreme caution and clearly understand what is at stake and the potential costs. 

Make no mistake, war between the West and Russia, even if it does not result in nuclear Armageddon, would be devastating, and not confined to the European theater. We can no longer idly toss around words for emotional and political gain. As we discuss NATO expansion, we must be clear that the remaining prior states of the old Soviet Union will not be admitted to the alliance. 

As for Sweden and Finland, we still need serious, rational, objective debate on the costs and benefits of admitting two historically neutral nations who have such strategic geographic position in relation to Russia. Before the Russian invasion, I would have said no. But given Russian actions, I have shifted from being against their admittance to NATO to neutral on the question, and will as a consequence vote “present.”

You can read the op-ed HERE.