TERRORIST WATCH LISTS AND THE ORLANDO ATTACK The Orlando shooter had been on the terrorist watch list, but then the case was closed against him — raising questions about whether the FBI simply missed the mark. The revelation highlights how difficult it is for authorities to try to guess which suspicions may develop into threats and which threats are the most serious, given that they have only hints of information; in this case, few people saw the signs of radicalization. And the FBI’s director says there is little he would have had his agency do differently.

Still, the uncertainty is likely to inform the debate in Congress as lawmakers wrestle with how to respond to the latest attack. One item on offer: using those lists — and giving the attorney general the authority to look beyond them — to at least prevent any suspected terrorist from obtaining a firearm, even if there is not enough evidence on hand to charge such a person with something. But the initiative is likely to split the parties, as many gun-control measures do.

APACHES ENTER COMBAT IN IRAQ Iraqi forces backed by the United States are encircling the key city of Mosul, and for the first time, U.S. Apache helicopter gunships are part of the fight. Obama authorized the use of the helicopters in Iraq in April to provide close air support as Iraqi forces push toward Islamic State strongholds, such as Mosul. They were last used in the country to help Kurds fighting for the Mosul Dam. The United States offered the Iraqis helicopters last year, but the prime minister initially turned down the offer. Obama has said he hopes that forces can retake Mosul by the end of the year.

NATO TO INCREASE DEFENSE SPENDING For the second year in a row, The North Atlantic Treaty Organization is going to increase defense spending, according to the Stars and Stripes newspaper, although the secretary general admits that “we are still far from where we need to be. And we clearly need to do more.” The driving forces behind this decision are a push to increase NATO’s presence in the Baltics and Poland, in response to a resurgent Russia. But it’s also a conveniently timed — whether related or not — response to a brewing debate in the United States about how NATO maintains relevancy, especially after the presumptive Republican presidential nominee, Donald Trump, called the organization “obsolete.” In his national-security-policy blueprint last week, House Speaker Paul D. Ryan (R-Wis.) also suggested that NATO countries had to think about spending more on defense to stay relevant. NATO’s policy is that member states dedicate 2 percent of GDP for defense spending — but in practice, the United States is one of the few countries to actually do so. More details about how NATO will increase its spending next year are expected when the alliance meets next month in Warsaw.