Though the peoples and cities the Romans conquered likely resented Roman subjugation, they could not deny that their lives were far more peaceful and orderly than they had been before. Roman law was rather fair and balanced for its time, and it was enforced by the armies of a mighty empire.
This became the trade Rome made with the people it conquered. They relinquished control of their government to Rome, and Rome, in exchange, provided them with justice and peace. This was a bargain most people could tolerate, and for 200 years, the Mediterranean fell under the sway of the Pax Romana. From 20 BCE to 180 CE, war within the empire was virtually unknown. In this era of peace, the provinces gradually became Romanized.
Roman standards of living, including roads, running water and culture, spread across the empire
Protected from invasion by the Roman army and secured in their property and persons by Roman law, the provinces were eager to gain the fruits of Roman civilization, like roads, running water, and culture.