Edit: https://news.ycombinator.com/item?id=32937782 links to claims that the Iranian government hacked WhatsApp or one of its networking providers.
Normally, that makes the service provider implement blocks on their end, because then at least they can present the user with a sensible error message, and other services that the government isn't trying to block are not impacted (eg. services hosted on the same servers - for example Whatsapp voice calls might be banned, but text chat not banned).
Ignoring the Iranian government might make them loose some users. Trying to ignore the US government will make some people go to prison. If that's what happens.. someone made a _very_ bad decision
The government is blocking at network level anyway.
The app provider should detect the network outage and provide a good UI, not proactively block users who aren't using the affected network at all.
Can the blocking be adequately distinguished from packet loss? If not it seems like it would be embarrassing for the app to declare Government blockage when it's not really the case.
How could any network-level block by Iran prevent a user in the UK from calling a user in India?