I believe that we're in decline because of the moral decay in our society. But we did surpass what the Romans did. Even in our decline we're still the worlds only superpower. All we have to do is reset our moral compass and turn back toward the teaching of the bible.
It's tempting to compare any modern power to Rome.There are lots of parallels. Roman leaders started out excusing invasions of other countries by saying they were defending the interests of their friends. They came to depend more an more on foreign imports. The leaders managed the lower classes by making the military a career (from Marius onward.) And, in 2004, when it appeared the US electoral system had failed and a dynasty was imminent, it was scary. However, the US hasn't stamped its name on the countries where it seeks influence, and the current administration appears to be supporting self-government for other countries' people and a stronger middle class in the US -- which was never a characteristic of the Roman empire.