Former Joint Chiefs chairman "sickened" by Trump's St. John's photo op

What he's saying: "I have to date been reticent to speak out on issues surrounding President Trump's leadership, but we are at an inflection point, and the events of the past few weeks have made it impossible to remain silent," Mullen wrote.

• "Whatever Trump's goal in conducting his visit, he laid bare his disdain for the rights of peaceful protest in this country, gave succor to the leaders of other countries who take comfort in our domestic strife, and risked further politicizing the men and women of our armed forces," he said. "There was little good in the stunt."
• "I remain confident in the professionalism of our men and women in uniform. They will serve with skill and with compassion. They will obey lawful orders. But I am less confident in the soundness of the orders they will be given by this commander in chief, and I am not convinced that the conditions on our streets, as bad as they are, have risen to the level that justifies a heavy reliance on military troops."

Go deeper: GOP senators scold Trump over St. John's photo op