With the Russian invasion of Ukraine now officially around the corner (or even underway), I am surprised how minimalistic and non-committal the proposed sanctions are. Even the US "mother of all sanctions" consists of mainly targeted surgical measures like cutting Russia off SWIFT and banning the export of semiconductors and the like. I understand that US doesn't have to show much of an effort since it's a long way from Ukraine to Washington, but I would expect much more resolve from the EU with a war on its doorstep.
EU sanctions against Russia have been ongoing since 2014. However, given their limited nature, Russia doesn't seem to have responded much to them (apart from learning to buy Russian apples instead of Polish ones).
Given that the EU-Russia trade comprises just 5% of all international trade of the EU but almost 40% of all Russian trade, I would naively expect that a total ban on trade and financial transactions would hurt the EU a little but bring Russia swiftly to its knees and Putin to the negotiating table. Of course, losing a third of the gas supply would mean everyone in Europe would have to put on an extra sweater or two and China would also likely step in and pick up part of the slack, but I cannot imagine Russia being able to retarget half of its foreign trade overnight.
(To illustrate my line of thought, consider how we treat bacterial infections with antibiotics. You don't slowly ramp up the dose because that would let the bacteria develop resistance, you hit them with a big hammer right away so they don't get a chance.)
I assume that if the above made a lot of sense economically, politicians would figure out a way to sell it to the general public (after all, they managed to sell things that didn't make any economical sense at all). Is there a serious economic analysis showing that targeted sanctions are more efficient than a total trade ban?