BOZEMAN, MT—Describing the San Francisco 49ers quarterback’s controversial decision to sit during the national anthem in protest against systemic racism as “shameful” and “a disgrace to our nation,” retired security guard Rick Arnold, 63, reportedly penned a critical open letter to Colin Kaepernick in the opinion section of his local newspaper Tuesday. “Dear Colin, I understand why you are doing this and that it is your right to protest. However, I know a thing or two about sacrifice, and your actions are misguided and disrespectful to all the Americans who have put themselves in harm’s way to keep this country safe,” wrote the one-time security officer tasked with monitoring the entrance of a commercial building and checking in new visitors, adding that sitting during the national anthem was an insult to all those he worked alongside who proudly served every day protecting the Pinnacle Industries office park. “I realize that this country certainly isn’t perfect, but a millionaire athlete making a fuss on the field won’t solve those problems. Publicly showing contempt for the American flag is a slap in the face to all the people who selflessly defend you and your rights. Think of the dangers people face every day on your behalf—I’d be happy to tell you all about them if you need a refresher.” The letter concluded by urging Kaepernick to apologize or Arnold would boycott the NFL this season.