If using US sourced components in aircraft leaves foreign manufacturers vulnerable to restrictions on who they can sell to, they may consider looking elsewhere. The alternatives may be more expensive or not as good but at least a deal could go through.
Sanctions like this can often have the effect of making alternatives, which wouldn’t otherwise have been viable, a realistic proposition. South Africa developed a sophisticated domestic armaments industry and even went onto become an exporter because of trade restrictions.
If the French, Chinese and Russians got together, within a few years American parts might not be needed at all.