"imposed threat" is correct and usable in written English.
It refers to a threat that is initiated by an outside entity or person. Example sentence: The imposed threat of the weather kept us from enjoying our picnic.
A more imposing threat to its membership is growing opposition in the United States.
The terror, the uncertainty, the threats, the divisions, and the more and more imposing threat of a new civil war.
But in its moment of triumph, the party faces an imposing threat, along with an implicit question: Did this hybrid of political party and political movement get too clever and overreach?
While a low-grade fever is better left un-medicated so the body can fight off the imposing threat of infection or illness that is causing the fever, at times and for high fevers, medication is recommended.
On December 30th a federal judge sided with the importers, preventing the administration from imposing "threat-based" safeguards.
This practice imposes threats to the ecosystem, i.e., physical, chemical, and biological components of the environment.
The windborne debris might perforate the fabric material, which not only results in total collapse of the structure, flying debris at high speed also imposes threats to people and facilities inside the structure.
Dynamic performance of concrete structures under blast loading conditions is a topic of importance as such load generates severe structural damage including flexural damage, shear damage and concrete spall damage which may impose threats to the personnel and instruments shielded by the reinforced concrete structure.
I had a vague sense of building outrage about the scale of the task being imposed, under threat, on a woman with poor literacy skills and two young children to look after.
At the time we felt endangered and did all that was needed to be done, within a hair's breadth short of war, to neutralize and remove the Russian imposed missile threat from Cuba.
