expression
for that very reason; that's exactly why
A somewhat formal or literary expression used to emphasize that a preceding statement is the very reason for what follows. Often used in explanations or arguments.
彼は努力を惜しまなかった。それなればこそ、成功したのだ。
He spared no effort. That's exactly why he succeeded.
この問題は複雑だ。それなればこそ、慎重に検討する必要がある。
This issue is complex. For that very reason, we need to examine it carefully.