Let's also stop comparing this to previous wars

First off, this is the first war where a madman has nuclear weapons and made it clear he will use them if anyone tries to stop his illegal invasion of a neutral country. I'll break that down for you:

1. Ukraine is not a member of either NATO or the European Union
2. Ukraine is a neutral country, which could be the best solution to this problem
3. The aggressor has threatened to use nuclear weapons if there is any foreign military action to help the invaded nation. 
4. This situation is allegedly about Ukraine joining international alliances (EU and NATO), but is really about economics and energy dependence (Or Banderists, Nazis, and drug dealers).
   

Nuclear weapons takes this out of the "let's look at the past" category.  Putin intends to freeze Europe by blocking natural gas, or frying it with nuclear weapons.

No matter how Putin cuts it, his actions may backfire if he doesn't back down. He's already pushed Ukraine to ask for EU membership. It's also hard to ask them to not join an organisation which would guarantee their independence (NATO).

 

Europe is dependent upon Russian natural gas, which is something that needs to change prestament. And Lukoil is the second largest company in Russia after Gazprom, and the country's largest non-state enterprise in terms of revenue ( ₽ 4,744 billion). In the 2020 Forbes Global 2000, LukOil was ranked as the 99th -largest public company in the world. Internationally, it is one of the largest global producers of crude oil. A boycot of Lukoil will harm its station owners outside Russia, but it is something which people need to be aware when they spend their money there.

The truth is that the West has no intention whatsoever of fighting against Russia to defend Ukraine. With the possible exception of Poland, NATO’s European members wholly lack the will to fight Russia unless NATO itself is directly attacked. President Biden and other leaders have made it clear that they will not do so, any more than the Obama administration fought for Ukraine in 2014 or the Bush administration for Georgia in 2008 — despite all the previous talk of partnership. The idea that Germany, France or Italy would do so is simply ludicrous. In these circumstances, to insist on holding the door open to future NATO membership for Ukraine is absurd, deeply unethical, and extremely dangerous both for Ukraine and NATO’s existing members.

The problem is that there needs to be a diplomatic solution to this instead of a military one, unless the military option is to use special forces to assassinate Putin. But that also has its drawbacks.

Short of a mutiny by Russia's military, we will see Ukraine fighting a much more powerful foe until the international community puts its foot down.

See also:

• Ukrainian neutrality: a ‘golden bridge’ out of the current geopolitical trap 
• Sur fond de crise ukrainienne, les Européens cherchent à réduire leur dépendance au gaz russe