Not really.
Shale isn’t that difficult, in general the pattern over the last decade has been to look for and extract harder to reach reserves (deep water etc). Shale is a new market entirely, at the cheap end it’s $25 per barrel equivalent.
If anything the USA is behind these moves as they’re far more effective than sanctions at bringing down governments.
Russian or Iranian oil isn’t necessarily expensive to extract, but their economies are built on that balancing the budget (a bit like the argument behind Sottish devolution). Typically the less you’re able to trade other goods/services with the rest of the world (i.e. we/’the west’ imposed sanctions) the more dependent you are on oil exports. Hence why you see numbers like Russia/Iran needing $110/$130 per barrel, it’s not the cost of extraction (which is probably $20-$30), it’s the ~$90 they need on top of that to keep the governments running, taxes low and populations happy.