The Tang dynasty fell after the people they had hired to fight for them, the Uighurs, turned on them instead and overthrew their government.
Soldiers hired into foreign service are called mercenaries. Write an essay
discussing why states that rely on hired mercenaries to fight for them
are often destroyed or are, at the least, unsuccessful. One example
from a later time is the Hessian soldiers who were hired by the British
to fight in the American Revolution. Imagine that you are leading a
state that is at war. If necessary, would you hire mercenaries to help
your state fight? Why or why not?