Wag the dog is, in politics, the act of creating a diversion from a damaging issue. It stems from the generic use of the term to mean a small and seemingly unimportant entity controls a bigger, more important one. The phrase originates in the saying "a dog is smarter than its tail, but if the tail were smarter, then it would wag the dog."
The earliest usage of the phrase in politics found in print seems to be an article originating in 1871, discussing one Democratic convention. In it, they reference a popular play, Our American Cousin, the very play that Abraham Lincoln was watching six years earlier when he was assassinated by actor John Wilkes Booth. In the play, the character Lord Dundreary is a sympathetic character who constantly utters confused catch phrases a-la Yogi Berra, which were known at that time as Dundrearyisms: The generic phrase, then and now, indicates a backwards situation in which a small and seemingly unimportant entity controls a bigger, more important one. It was again used in the 1960s, as in the economic advice "don't let the tax tail wag the investment dog". The term gained political clout in the 1990s, starting with the success of the 1993 novel Wag the Dog. In 1997, a film came out based on that novel, Wag the Dog. In it, a president was failing in his re-election bid, and came up with the scheme of using military action to save his campaign. This became a "reality" the year after it was released, when Bill Clinton faced impeachment during the Monica Lewinsky scandal, where he was caught in the felony of committing perjury. Days after the scandal broke, Bill Clinton ordered missile strikes against two countries, Afghanistan and Sudan. During impeachment proceedings, Clinton also bombed Iraq, drawing further "wag the dog" allusions. With the scandal still on the public's mind in March 1999, his administration launched a bombing campaign against Yugoslavia. This concept has then been brought up for each subsequent president, multiple times for Donald Trump, including in April 2017 when he conducted airstrikes against Syria during an investigation of Russian interference in the 2016 United States elections. Then in January 2020, after a U.S. airstrike assassination of Iran's Gen. Qasem Soleimani occurred during Trump's impeachment process, various references to Wag the dog made the news. Many referred to several tweets by Trump from 2011–2012 suggesting President Obama would essentially "wag the dog" to get re-elected, noting the hypocrisy of the current situation.