The phrase "pose a threat" is correct and usable in written English. It is typically used to refer to a situation in which there is potential for something dangerous or harmful to occur. For example, "The storm could pose a threat to the safety of our community."
Do these people pose a threat?
Even so, nature can pose a threat.
Do they pose a threat?
And others pose a threat.
Brazil will also pose a threat.
He does not pose a threat".
Russians continue to pose a threat.
Nor does North Korea pose a threat.
These "populisms" pose a threat to modern liberal democracy.
Aphids can pose a threat to winter greens production.
"The economy doesn't currently pose a threat to your job.
I love the desktop app, it’s always running on my Mac. Ludwig is the best English buddy, it answers my 100 queries per day and stays cool.
Cristina Valenza
Retail Lead Linguist @ Apple Inc.