Worldly Kingdoms

Keep in mind it was Satan with the power to place Vespasian and Titus in positions of authority, as God allowed him the right to involve himself in governments. This is certain because Satan offered the governments to Jesus.

Mat 4:8 Again, the devil taketh him up into an exceeding high mountain, and sheweth him all the kingdoms of the world, and the glory of them;

Mat 4:9 And saith unto him, All these things will I give thee, if thou wilt fall down and worship me.

All kingdoms exist because of God's will, and these would play into God's hands as he allowed kingdoms that would test and challenge his people. Not necessarily for temptation, but for Christian growth as he matures our faith. We are required to put more trust in him and rely on his power to overcome satan. God allowed Job to be tried to bring him to a higher understanding through his friends questions. God allowed Satan authority to test and mature Christians to faithfulness.

Joh 19:11 Jesus answered, Thou couldest have no power at all against me, except it were given thee from above: therefore he that delivered me unto thee hath the greater sin.

Kingdom's were born to carry out God's plan, but kingdom's did not relieve us of our personal responsibility. As those who delivered Jesus to the Romans would bear their sin.

Satan did indeed exercise a kingdom.

Mat 12:26 And if Satan cast out Satan, he is divided against himself; how shall then his kingdom stand?

Many Jews and Christians came to side with Vespasian, and became informants for his cause.