Well I make that assumption based upon - personal testimonies and general assessments of the state of the Church from American Christians, such as Watchman, and Americans I know personally. Comparison of these testimonies against my experience and testimonies of the state of the church in my own country, and other countries around the world. Which I might add, seem to be far less immoral or corrupt than what i hear happening in the USA. Did you know australia doesnt' allow gay marriage? Comparison of Western Christianity with Christianity in China for example, and other places where the church is said to be exploding. The fact that most false doctrine that I see on my TV screen is American tele-evangelism, not British, or Chinese, or Australian. Majority of false doctrine comes from America I do believe. Via books, television, CD's, DVD's etc. Logically, if a country of such power, size and world influence as the US, is at the forefront of good in the world, they are also mostly responsible for most of the evil. I wouldn't say it's my assumption, it's my well-learned and researched observation.