Hello LWT,
Here's is a passage to bear in mind from the ESV Study Bible and study notes
Romans 13
Submission to the Authorities
13 Let every person be subject to the governing authorities. For there is no authority except from God, and those that exist have been instituted by God. 2 Therefore whoever resists the authorities resists what God has appointed, and those who resist will incur judgment. 3 For rulers are not a terror to good conduct, but to bad. Would you have no fear of the one who is in authority? Then do what is good, and you r will receive his approval, 4 for he is God's servant for your good. But if you do wrong, be afraid, for he does not bear the sword in vain. For he is the servant of God, an avenger who carries out God's wrath on the wrongdoer.
Rom. 13:4 Governing authorities are God's servants and carry out his wrath on evildoers, and they do so for your good. Even though Christians must not take personal revenge (12:17–20), it is right for them to turn punishment over to the civil authorities, who have the responsibility to punish evil. The reference to the sword most likely refers to the penalty of capital punishment (cf. Gen. 9:6).
I haven't thought about the issue much but was it right to war against Hitler in WWII? IMHO, undoubtedly.
I agree with the ESV notes here once again
Luke 6:29
29 To one who w strikes you on the cheek, offer the other also, and from one who takes away your cloak do not withhold your tunic [1] either.
Luke 6:29 strikes you on the cheek. An insulting slap (cf. note on Matt. 5:39). Offer the other also is not intended as a command for every circumstance (Luke 6:30) but is a vivid illustration of how love for one's enemies should look. This verse should not be understood as a prohibition against governments using military or police force, since in this context Jesus is addressing individual conduct. takes away your cloak. The point of both examples is that, even though believers will often be subject to abuse or taken advantage of, they are to face such rejection differently from the world, that is, by being generous and compassionate rather than retaliating.
The WT take this teaching to the nth degree and totally distort it, as they do other NT teachings, 1 Corinthians 5 etc.
Blessings,
Stephen