If you shut it down for too short and there is a lapse in extending the grounding, planes are getting shot out of the sky (or whatever threat it was).
edit: I would add that maybe there are forms for shutting down airspace of various specific time lengths and a convenient time for something of unknown duration would be 10 days. 10 days might also be enough time to be sure whatever resources need to be brought to bear on this are available where an hour or day might not be. Shut it down basically indefinitely, or at least long enough that the crew who handles this extraordinary situation will be on hand to turn it off.
> The brief shutdown was related to a test of new counter-drone technology by the military at nearby Fort Bliss Army base, according to a person briefed on the matter.
> According to a social media post by the Secretary of Transportation, Sean Duffy, Mexican cartel drones breached U.S. airspace, prompting temporary closure of airspace over El Paso. The Defense Department took action to disable the drones, Mr. Duffy said. Another person familiar with the situation had described the cause of the shutdown as a test of anti-drone technology. It is unclear if the brief airport closure was directly related to the presence of drones or how the technology was deployed.
It does not seem implausible or unreasonable to me that an anti-drone system would trigger airspace restrictions when activated. Whether system activation is intended to put out a 10 days block is probably a different issue, but probably related to SOP for an event of unknown duration.
"Never attribute to malice that which is adequately explained by stupidity."
Someone probably just screwed up
They had plans to bomb something south of that airport, they had to postpone those plans now that the info is public enough that whatever their target was is definitely aware of those plans.
I don't, and since neither of us can know for sure given the info we've been given, it's useless for us to argue about our opinions.
https://www.cbsnews.com/news/airspace-closure-followed-spat-...
Liz Truss begs to differ.