Cutting Russia from SWIFT is not like cutting Iran off. Russia is way richer with far more reach and cutting more and more countries off of the network will give more and chance for one of the alternatives to grow.
Cutting Iran from SWIFT has also just created pressure on Iran to not rely on foreign economies too much. And you can see this by how they've essentially become immune to more sanctions, or global economic termoil.
Honestly cutting Russia off of SWIFT is going to create a much more dangerous Russia in the next few decades.
Yes, it's an age-old dilemma, to try to soften the aggressor or to stand up to him. Delaying the confrontation hoping something will change for the best vs standing the ground and fighting back.
Some lessons from the not that recent history might suggest that choosing the former might lead to quite a disaster.
I was surprised to learn that the GDP of Russia is barely higher than the combined GDP of Luxembourg, Belgium an the Netherlands, three relatively small EU countries. Russia is a big country, has a large population, a populous army, but is relatively poor. War is expensive.
Measuring GDP as richness isn't really useful. Russia doesn't operate a war on USD or EUR. This is like comparing income without taking into account cost of living.
GDP is not a good measure of richness of a country in relation to how it will handle itself in a war.
This is another huge mistake from the Western liberal order that keeps fumbling the ball.
Relying on Russian gas for energy security was the first.
What are the root causes if these disastrous decisions? How did the East get smarter, more Machiavellian than us? They were in the trash can 20 years ago. Perhaps getting fat and rich rather than fighting for every penny.. we are missing street smarts, and end up with Justin Trudeau
Many people (most?) consider "Machiavellian" to be an insult - essentially synonymous to "smart but immoral". Part of the West's ideology, for better or worse, is the idealistic belief that smartness and simple prudence/shrewdness can be separated from the negative aspects of Machiavellianism.
There's also recognition of the valid circumstance in which you're presented with choosing a lesser evil. If all choices are bad, choose the least bad, and those contexts change radically over different time frames.
Extend NATO membership to more countries and get them on if they want to in less than a month.
Bring Iran back into the world economy, get them away from Russia. Use them for energy, etc.
Deploy iron dome across eastern europe.
Get a UN-led referendum in various natural localities of Ukraine to decide if they want to be a part of Russia or not. Anywhere that isn't, get them to join NATO. Anywhere that is, well, let people decide which govt they want to belong to.
Playing devil's advocate, are you sure that strangle a nuclear-powered country with vast resources and possibly pushing them into form a coalition with other countries will be a good idea? This will further polarize the world and resentment will run deep after some years. Heck, This looks really similar to the origin story of Hitler just with nuclear bombs as blitzkrieg.
Honestly cutting Russia off of SWIFT is going to create a much more dangerous Russia in the next few decades.