Contradiction with Matthew 5:44
Deuteronomy 20:12 commands to besiege a city if it does not make peace, while Matthew 5:44 instructs to love your enemies and bless those who curse you.
Matthew 5:44: But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;
Contradiction with Romans 12:18
Deuteronomy 20:12 involves engaging in warfare when a city does not seek peace, whereas Romans 12:18 advises to live peaceably with all men as much as possible.
Romans 12:18: If it be possible, as much as lieth in you, live peaceably with all men.
Contradiction with Proverbs 15:1
Deuteronomy 20:12 implies resolving conflict through siege warfare, while Proverbs 15:1 suggests that a gentle answer can turn away wrath.
Proverbs 15:1: A soft answer turneth away wrath: but grievous words stir up anger.
Contradiction with James 3:17
Deuteronomy 20:12 involves taking aggressive action against a non-peaceful city, in contrast, James 3:17 highlights that wisdom from above is peaceable, gentle, and open to reason.
James 3:17: But the wisdom that is from above is first pure, then peaceable, gentle, [and] easy to be intreated, full of mercy and good fruits, without partiality, and without hypocrisy. [partiality: or, wrangling]
Paradox #1
Deuteronomy 20:12 could raise concerns about the morality of warfare and treatment of enemies in contrast to other passages that emphasize mercy and love for others, such as those found in the teachings of Jesus in the New Testament. This creates a tension between Old Testament commands concerning warfare and New Testament teachings on peace and forgiveness.
Paradox #2
The contradiction or conflict might be the idea of using force or violence to achieve peace, which can be seen as inconsistent with teachings about love and forgiveness in other parts of the Bible.