Mueller's investigation

• A top FBI investigator left Special Counsel Robert Mueller's investigation team, per ABC's sources. "The recent departure of FBI veteran Peter Strzok is the first known hitch in a secretive probe that by all public accounts is charging full-steam ahead," Mike Levine of ABC reports.
• Strzok, who was part of the team that investigated Hillary Clinton's private email servers, is now working for the FBI's human resources division. His reason for leaving the Russia probe is unclear.

The opioid emergency

• "The opioid crisis is an emergency, and I'm saying officially, right now, it is an emergency ... It's a national emergency. We're going to spend a lot of time, a lot of effort and a lot of money on the opioid crisis," Trump said last week. But, in the week following his announcement, the president has not taken the legal steps necessary to implement national emergency protocol.
• The steps: Trump first needs to give official notice to Congress that he is declaring a national emergency. Then the declaration is published in the Federal Register.
• The unknowns: Without an official declaration, it is unclear how the Trump administration plans to respond to the opioid crisis. It could be a mobilization of medical resources or a mobilization of law enforcement — two very different things, Rachel Sachs, a law professor at the Washington University in St. Louis, told Axios.

The North Korean threat

• North Korea backed off of Guam on Monday after threatening to launch missiles at the U.S. territory.
• Trump's "fire and fury" comment may have helped, Rand political analyst Andrew Scobell told CNBC. "I think the rhetoric from the president does register in Pyongyang, and it has been noted in Beijing," Scobell says.
• Trump tweeted: "Kim Jong Un of North Korea made a very wise and well reasoned decision. The alternative would have been both catastrophic and unacceptable!"

NAFTA renegotiations

• The U.S. perspective: In the renegotiation of the 23-year-old trade deal, the United States' goals are to reform "problems perceived by Trump, such as trade deficits, rules of origin, currency manipulation and market-distorting practices," CNBC reports. "I want to be clear, [the president] is not interested in a mere tweaking of a few provisions," U.S. Trade Representative Robert Lighthizer said.
• The Mexican perspective: "While Mexican government negotiators fought tooth and nail to save the North American Free Trade Agreement during talks in Washington, thousands of Mexican farmers and workers took to the streets on Wednesday demanding the deal be scrapped," per Reuters.
• The Canadian perspective: One White House goal is "scrapping NAFTA's dispute-resolution panels, which have sometimes ruled in Canada's favor on softwood lumber and other trade issues," according to Canada's Globe and Mail. Canadian officials will inevitably challenge this, as they have done in the past.