I would say yes, when there is the political will to do so....
Very quickly following Russia's 2022 invasion of Ukraine, Canada announced a position. As far as I understand, this wasn't legislated. This wasn't a regulation, but a new position that Canadian officials were going to immediately stop the further issuance of export permits for any controlled goods to Russia and actually revoke existing permits. That is essentially as far, typically, as our officials will go as it relates to export controls. This happened in a matter of days, I would say.
When something happens, there certainly are mechanisms to stop the future provision of weapons and to cancel permits that allow any weapons exports that have been approved.
Other examples where this has happened would be Belarus in 2019, as well as Turkey in 2019 and further in 2021.