also: とあらば
conjunction
if it is the case that; if
A formal or literary conditional conjunction. Used to present a premise or situation as the basis for a following statement, often with a nuance of 'given that' or 'since it is the case that'. More emphatic than なら or であれば.
彼が来るとあれば、準備を整えなければならない。
If it is the case that he is coming, we must make preparations.
必要とあれば、いつでも手伝います。
If it is necessary, I will help anytime.