Because suddenly the oil isn't Russian anymore but Indian or something like that. Here's[1] an article going into how after the 2014 sanctions suddenly a lot of tropical fruits started growing in Belarussia, or how the landlocked country suddenly started exporting tons of Belarusian shrimp.

[1]: https://east-center.org/wp-content/uploads/2018/01/Belarus-E...

Europe kept buying Russian oil and gas, because other sources could not come online quickly enough. Tariffs would have only made energy even more expensive than it already was. Now it's mostly Hungary and Slovakia buying Russian energy, as well as some LNG imports. Those two countries are not too keen on sanctioning Russia, especially in ways that would hurt their economy. Any attempts to impose tariffs on energy imports from Russia would have led to a major internal crisis in the EU.

The US already started to pressure these two. We'll see how it goes. Ukraine could always blow up or sabotage the pipelines or some of the pumping stations if they think it's appropriate, either in Russia or on their own territory.

It’s frankly a pretty bold bet to count on these pipelines existing for years to come. It might have been smarter for Hungary and Slovakia to scramble for other sources of energy, starting March 2022.

> Europe kept buying Russian oil and gas, because other sources could not come online quickly enough

They did do sanctions, so I don't know what you're trying to argue.

> Tariffs would have only made energy even more expensive than it already was.

Not as expensive as outright sanctions, of course.

As I said - sanctions are discrete (yes or no), whereas tariffs are a continuous knob.

There were essentially no sanctions impacting Russian energy exports to Europe. Those would have hurt Europe much more than Russia. If you can't export something, the damage is proportional to the volume of the exports. But if you don't have enough energy, your entire economy suffers.

The increases in energy prices mostly came from voluntary attempts to find alternatives to Russian energy and from Russia constraining the supply.

Why would Russia voluntarily give up money by constraining the supply during the war? That makes absolutely no sense.

Coersion. A comparatively small amount of revenue being given up could scare Europe away from supplying Ukraine with materiel. The Russians put out ads about how Europe would be freezing through winter.

> Why not tariffs? Basically the continuous version of discrete sanctions

There are still some qualitative differences: With sanctions, you'll know something dodgy has occurred when you find a pallet of My Little Putin dolls traveling through the port, you don't need to call up a bunch of lawyers and accountants.

That said, I readily admit that oil is a lot more disguise-able and fungible.