expression
if that happens; if that is the case; when it comes to that
Used to introduce a consequence or a natural next step when a certain situation arises. Often implies 'in that case' or 'then'.
そうなると、計画を変えなければならない。
If that happens, we'll have to change the plan.
そうなると、彼はもうここにはいられないだろう。
If it comes to that, he probably won't be able to stay here anymore.