Libertarian presidential nominee Gary Johnson raised eyebrows and dropped jaws Thursday when he asked the hosts of Morning Joe what Aleppo was in response to a question about his policy on Syria.

While Mike Barnicle responded with, "You're kidding," Joe Scarborough was even harsher. "My god, can you believe it?" he asked the other hosts following the commercial break. Scarborough added that Johnson is "unqualified to be the president of the United States" due to his "stunning" ignorance about Aleppo.

Johnson, for his part, has canceled some of his other scheduled television appearances on Thursday, The New York Times reports. "I'm incredibly frustrated with myself," he told MSNBC after his Morning Joe appearance. "I have to get smarter and that's just part of the process."

Johnson would need to poll at 15 percent to make it onto the debate stage beside Hillary Clinton and Donald Trump; as of four days ago, he was polling at 10 percent, according to Pew. Jeva Lange

President Trump came under broad criticism Saturday for his decision to pardon Joe Arpaio, the controversial former sheriff from Arizona who was convicted of criminal contempt of court for refusing to comply with a court order to stop detaining people purely on suspicion that they might be illegal immigrants.

Trump caught flak from Republicans in both houses of Congress, including Arpaio's fellow Arizona Republican, John McCain:

Democrats piled on, too. House Minority Leader Nancy Pelosi (D-Calif.) said the pardon "makes mockery of rule of law," while Sen. Ron Wyden (D-Ore.) leveled a more serious charge:

Arpaio, meanwhile, thanked Trump for "seeing my conviction for what it is: a political witch hunt by holdovers in the Obama justice department!"

For more on Arpaio's record of prisoner mistreatment and racial harassment, see this breakdown of the pardon's disturbing implications from The Week's Scott Lemieux. Bonnie Kristian

Secretary of Defense James Mattis is seen in a video posted Thursday on a Facebook page called "U.S. Army W.T.F! moments" encouraging U.S. troops to "hold the line" in the face of rising political tension in the United States.

"Our country right now, it's got problems we don't have in the military," Mattis says. "You just hold the line — my fine young soldiers, sailors, airmen, Marines — you just hold the line until our country gets back to understanding and respecting each other and showing it."

"We're so doggone lucky to be Americans," Mattis continued. "We've got two powers, the power of inspiration, and we'll get the power of inspiration back. And we've got the power of intimidation, and that's you, if someone wants to screw with our families, our country, and our allies."

Mattis is currently on an overseas tour with stops in Ukraine, Turkey, Jordan, and Iraq, and it is unclear where his apparently impromptu speech occurred. Watch his comments in context below. Bonnie Kristian

A U.S. military helicopter crashed during a training exercise off the coast of Yemen Friday, U.S. Central Command reported Saturday. Five of the six U.S. troops on board were rescued, and the search for the sixth person is ongoing.

The cause of the Black Hawk helicopter's crash is unknown. "Commanders deemed this location appropriate and safe for a routine training event," Centcom said, "considering both the operational environment and weather conditions at the time."

The U.S. conducts anti-terror airstrikes in Yemen and supports a Saudi-led military intervention that has contributed to the country's grave humanitarian crisis. Bonnie Kristian

A man brandishing a sword and yelling "Allahu Akbar" was arrested Friday night outside Buckingham Palace, the residence of Queen Elizabeth II in London. Three officers suffered minor injuries during the arrest, and the incident is being investigated as a possible terrorist attempt. The suspect is 26 and hails from Luton, north of London.

A "car deliberately drove at a police van and stopped in front of it in a restricted area," said a statement from London police. As the officers from the van "challenged the driver, who was the only occupant in the car, he reached for what we now know to be a four-foot sword" before being incapacitated with tear gas. Bonnie Kristian

President Trump's Twitter feed was dominated by posts about Hurricane Harvey Friday and Saturday, with the president posting warnings about the extreme weather while praising his administration's response to the storm so far.

The largest storm to hit the United States in a decade, Harvey is considered an important test for the Trump administration. "In an instant, natural disasters can become defining moments for a presidency," notes CNN's Jeremy Diamond. For example, "Hurricane Katrina, which hit the New Orleans area in August 2005, became a defining moment of [the George W. Bush] administration, whose response to the hurricane was marked by a series of errors in preparation and mismanagement that sent the president's approval rating to record lows." Trump's approval rating is already at record lows, so a fumble here could send him below 30 percent.

Federal Emergency Management Agency (FEMA) administrator William "Brock" Long is new to his post — he was confirmed by the Senate in June — but he has prior FEMA and state-level emergency management experience and is respected in his field. One of Trump's Saturday tweets, below, praised Long while reminding him "the world is watching." Bonnie Kristian

President Trump signed a memo Friday directing the Pentagon to implement the ban on transgender troops he unexpectedly announced in late July. The document says the Defense Department (DoD) must stop accepting openly transgender recruits but allows Pentagon leadership to decide whether active transgender personnel can continue in their roles.

The memo also prohibits federal spending on sex-reassignment surgeries unless they are needed "to protect the health of an individual who has already begun a course of treatment to reassign his or her sex." The DoD has six months to decide what to do about current transgender personnel.

Trump's apparently impromptu July announcement has come under broad criticism in subsequent weeks. "Any American who meets current medical and readiness standards should be allowed to continue serving ... regardless of their gender identity" said Sen. John McCain (R-Ariz.).

McCain's Democratic colleague, Sen. Tammy Duckworth (Ill.), released a widely shared statement Thursday referencing her own military experience to oppose the ban. "When I was bleeding to death in my Black Hawk helicopter after I was shot down, I didn't care if the American troops risking their lives to help save me were gay, straight, transgender, black, white or brown," she said. "All that mattered was they didn't leave me behind." Bonnie Kristian

North Korea tested three short-range missiles Saturday morning. The first and third tests flew about 155 miles before they "failed in flight," U.S. Pacific Command reported, while the second missile "appears to have blown up almost immediately." None of the tests posed any threat to the mainland United States or the U.S. Pacific island territory of Guam.

North Korean state media reported leader Kim Jong Un also visited troops on Saturday, telling them to "think of mercilessly wiping out the enemy with arms only and occupying Seoul at one go and the southern half of Korea."

For a deeper look at Pyongyang's armament ambitions, see this analysis from The Week's Becca Stanek. Bonnie Kristian