Why does a marriage outside the Church need to be annulled?

My understanding is that if a person marries a non catholic, that it is necessaary for that person to nullify their previous marriage even if they are legally divorced. If the Catholic Church does not recognize marriage outside the church, then why must that person nullify their previous marriage:thankyou:

The following link should help you better understand the Church’s teachings on marriages outside the Church and annulment. If you have any further questions, please contact Catholic Answers directly.

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Why a Catholic Church annulment?

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