Collocations for ally - noun

great, important, key, powerful, strong
close
Charles remained a close ally of the French king.

loyal, reliable, staunch, trusted
natural, strategic, useful, valuable
long-time (esp. AmE), old, traditional
Portugal is a traditional ally of England.

erstwhile, former
wartime
potential
European, NATO, Western, etc.
political

have
Lois felt that she had an ally.

find, gain, get
alienate, lose

ally against
He now had an ally against his boss.

find an ally in sb, have an ally in sb
She had found an ally in her old teacher.

a friend and ally
a friend and ally of the president