Where. To. Begin. Meme has long had a problem with countrywank. Generally, it stems from one of two issues, each of which can be represented in two different ways: an American using “us/we” to mean the other American anons and thinking everyone would understand (or a US-centric American assuming the entire meme is American); or a non-American saying something critical of the US (or a non-American bashing the US).
Here's an early (July 2010) discussion of "USian" vs. "American", which didn't turn into wank. Other early mentions of US-centrism are here and here. A day later, things started getting angrier.
In early September 2011, countrywank sparked anti-Romani racewank and defenses of the French burqa ban, Dominique Strauss-Kahn, and France's refusal to take in Tunisian refugees….which started Islam wank. The entire thread was frozen.
In late November 2011, after this explosive countrywank followed by this troll attempt to reignite it (which was frozen), the mods declared "Country Wank Off Topic for the rest of this post."
In March 2013, a nonny tried to ignite countrywank with a thread called "Let's Settle This." The thread drew a particularly noxious xenophobic American troll, whose subthread was frozen. On the plus side, the overall thread gave us a discourse on Trolliana agitatus.
In April 2014, FFA enjoyed what was nearly the the platonic ideal of countrywank, which began here and eventually evolved into a flamewar over whether Italy or Texas is more diverse. Almost as impressive was Cheque Wank in May of the same year.
In May 2015, a thread titled “Vent about US centricism in the wild" ran to 571 comments.
In February 2016, for the new-ish common thread “Country of the Post,” a nonny declared, "The country of the post is the United States of America!" 724 comments ensued, most of them wanky.