Putin failed to create a diverse economy and instead relied on exporting natural resources (part of his "thesis" he wrote for the KGB studies), so this can hurt

Putin failed to create a diverse economy and instead relied on exporting natural resources (part of his "thesis" he wrote for the KGB studies), so this can hurt him. Germany, on the other hand, needs to diversify their oil and gas imports to gain more independence from Russia for geopolitical reasons, as the Russian government has just illustrated that they are dangerous and unreliable. So the step makes sense. It doesn't suffice, though. The sanctions would have to be all-encompassing, similar to the ones that were imposed on Iran, in order to have a strong effect.