le does not mean it was not a red line.
I consider any such "If"... "then"... type of threat to be a red line.
Here is the "if" statement:
"North Korea best not make any more threats to the United States."
and in that context, within 3 hours North Korea clearly makes a big threat against the United States & releases a video with U.S. officials engulfed in flames and Trump looking out over a cemetery:
https://www.washingtonpost.com/news/worldviews/wp/2017/08/21/north-koreas-latest-video-tirade-reignites-missile-threat-against-guam/?utm_term=.77006a0affaf
In this excerpt from a North Korean propaganda video, senior U.S. officials are seen engulfed in flames with President Trump looking over a cemetery with the warning: “The fate of the U.S., with its many crimes, ends here.” (The Washington Post)
I don't see how that can reasonably be interpreted as anything other than a red line threat by Trump, which was immediately crossed by North Korea. A clear thumbing of the nose to Trump's threat.
I think Trump let his mouth run away from him again and embarrassing himself thereby.