Everything I told you came from sources I looked up online, to confirm what DC Comics and Warner Bros. in general had done with the character. Many other adaptations of the Superman story never used the full phrase - "Lois & Clark", "Smallville", the 2006 film "Superman Returns"...none of them used the "American Way" segment. There was also a different version used in a 1948 serial production, spoken as "Truth, Tolerance, and Justice". Action Comics Vol. 1 #900, from June 2011, is the issue where he (in)famously gives up his citizenship. But there's a quote in the actual issue that clarifies his reasons for such a choice, in the context of the story...
"I intend to speak before the United Nations tomorrow and inform them that I am renouncing my U.S. citizenship. I'm tired of having my actions construed as instruments of U.S. policy. "Truth, justice, and the American way - it's not enough anymore. The world’s too small, too connected."
That said, I also came across this image, on DC's actual website. Its from a school book cover used in 1949, distributed to schools by the Institute for American Democracy, an offshoot of the Anti-Defamation League. The artwork is assumed to be from artist Wayne Boring, but origin of the message's text itself remains unknown. So clearly, both positions have been held at different points in history - its not a one-sided problem.