I think Western leaders are clear headed enough to understand that sanctions do not cause people to raise against their leaders. This has been known since bombing Germany and Japan in WWII (a different, more violent kind of sanctions). However sanctions weaken the adversary technologically, economically, and ultimately militarily. This is a pragmatic reason to enforce sanctions on the adversary.
That's reasonable for a "short term" military conflict, but if you keep a country under sanctions for decade and deliberately reduce the quality of life in that country, that's essentially a message to the population that they don't count.
