just a question of something something

Từ điển Oxford Advanced Learner 8th

just/merely/only a question of (sth/doing sth) idiom
used to say that sth is not difficult to predict, explain, do, etc.
• It's merely a question of time before the business collapses.
•It's just a question of deciding what you really want.
Main entry: ↑question_idiom