Here’s the reasonable argument: US citizens are now used to .gov domain names being solely used by US government entities. They won’t change it, nor should they, as forcing domain name changes will simply add confusion for Americans.
Just because you don’t like that the US government has first mover advantage isn’t a good reason to change this.
I don't really think this is much of an issue. It's not like the change would happen immediately. Each .gov website is likely run by different agencies, so they wouldn't end up switching all at the same time.
It's a pretty simple matter to register a corresponding .gov.us domain for each existing .gov domain. Then each .gov domain owner would have to configure their web server properly, and can phase in a redirect from the old .gov to the new .gov.us.
Prior to this happening, the .gov site could have a big banner across the top of the page informing visitors of the change. This could remain for as long as seems reasonable before changing, even multiple years.
> Just because you don’t like that the US government has first mover advantage isn’t a good reason to change this.
As an American, I think the current setup with .gov (and .mil) is super weird. The fact that there are so many US government websites that are under .com, .org, and even .us, is weird too. The US shouldn't hold any kind of privileged place when it comes to TLDs; it's clearer for everyone concerned -- including Americans -- to put all these under .gov.us.
MS still hasn't gotten all of their users to transition to outlook.com in order to be rid of hotmail.com, which they bought in 1997.
Do you have the US Government doing it quicker? The only way it ever occurs is if they effectively CNAME .gov to .gov.us to run them both side-by-side.
Just because you don’t like that the US government has first mover advantage isn’t a good reason to change this.