Overnight Defense: Trump, Biden set to meet in final debate | Explicit Fort Bragg tweets were sent by account administrator | China threatens retaliation over Taiwan arms sale

Happy Thursday and welcome to Overnight Defense. I’m Rebecca Kheel, and here’s your nightly guide to the latest developments at the Pentagon, on Capitol Hill and beyond. CLICK HERE to subscribe to the newsletter.

THE TOPLINE: The second and final presidential debate of the 2020 campaign is Thursday night, and it will ostensibly be the more foreign policy and national security heavy of the two.

One of the six announced topics for the debate is national security, and foreign policy could also come up during other topics such as the pandemic, climate change and leadership. The Trump campaign, though, complained earlier in the week the whole debate wouldn’t be about foreign policy.

Stay tuned to TheHill.com tonight for full coverage of the debate.

In the meantime, get ready for the debate with our previews.

The Hill’s Morgan Chalfant and Brett Samuels took a look at how the debate presents Trump with one last major chance to meaningfully alter the trajectory of the presidential race.

The first contest between the two descended into chaos and was viewed by Republicans as a missed opportunity largely of Trump’s own making. The final debate will feature a new rule allowing both candidates’ microphones to be muted at the start of each segment after Trump repeatedly interjected as Biden spoke in the first debate in Cleveland. 

Trump and his allies have spent the week leading up to the debate attempting to lower expectations for the president by preemptively attacking the moderator, NBC’s Kristen Welker, and accusing the debate commission of shielding Biden from scrutiny.

Thursday’s debate comes at a time when the final result is increasingly out of any candidates’ control. Many Americans have already cast their ballots by mail or headed to the polls for early voting.

The Hill’s Max Greenwood also ran down five things to watch for in the debate. Catch up on that here.

FORT BRAGG WASN’T HACKED: Many eyebrows were raised Wednesday when some sexually explicit tweets were sent out from the official Fort Bragg Twitter account.

The Army base originally attributed the tweets to a hack.

But as it turned out, the tweets were sent by someone who had access to the account.

A spokesman at the North Carolina base said Thursday an administrator of the account admitted to sending the tweets, which were graphic replies to a sex worker’s tweets.

“This morning, at the initiation of an investigation into yesterday’s incident regarding inappropriate tweets on the Fort Bragg Twitter account, an administrator for the account identified himself as the source of the tweets,” Col. Joe Buccino, a spokesperson for the XVIII Airborne Corps, said in a statement Thursday.

“Appropriate action is underway,” he added.

CHINA FUMES ABOUT TAIWAN ARMS SALES: As expected, China is not happy about the United States’ latest arms sales to Taiwan.

On Thursday, China threatened retaliation after the Trump administration approved the $1.8 billion arms sales.

Chinese Foreign Ministry spokesperson Zhao Lijian accused the U.S. of “interfering” in Beijing’s affairs and said the sale could lead to regional insecurity.

“It seriously interferes in China’s internal affairs, seriously harms China’s sovereignty and security interests, sends out gravely wrong signals to Taiwan independence forces and severely undermines China-US relations and peace and stability across the Taiwan Strait. China firmly opposes it,” Zhao said.

Zhao urged the U.S. to “stop arms sales to and military ties with the Taiwan region, cancel its arms sales plans to avoid further harming China-US relations and cross-strait peace and stability,” warning that “China will make a legitimate and necessary reaction in the light of the development of the situation.” 

Zhao also sought to cast doubt on Taiwan’s position that it has no interest in engaging in an arms race with mainland China.

“If they truly don’t want to engage in an arms race, then they should match their words with actions, instead of saying one thing and doing the opposite,” he said. 

DEMS BLAST OPEN SKIES WITHDRAWAL: With so much happening, it’d be easy to forget that Trump’s withdrawal from the Open Skies Treaty, which he announced in May, is just less than a month away from becoming official.

On Thursday, House Foreign Affairs Committee Chairman Eliot Engel (D-N.Y.) and Rep. Bill Keating (D-Mass.) put out a statement warning of the “fast approaching” official withdrawal.

They also continued to blast Trump for not submitting the notification to Congress that last year’s annual defense policy bill required.

“At every step of the way, this president has ignored the advice of diplomats, defense experts, and our allies and partners while his notification of U.S. withdrawal from the treaty flagrantly broke the law that he himself signed,” they said. “If the administration is insistent on making this reckless decision, it should submit its official notice to Congress and wait the requisite 120 days before withdrawing from the treaty. The American people, and our allies and partners, deserve at least as much.”

ON TAP FOR TOMORROW

Rep. Anthony Brown (D-Md.) and Bell CEO Mitch Snyder will speak at an online Brookings Institution event on “The defense industrial base and the future of warfare” at 10 a.m. https://brook.gs/34jqZ20

Will Roper, assistant secretary of the Air Force for acquisition, technology and logistics, will speak at the closing ceremonies of the virtual Air Force Rapid Sustainment Office Advanced Manufacturing Olympics at 1:40 p.m. https://bit.ly/3ohnwZA

Lt. Gen. B. Chance Saltzman, deputy chief of space operations for operations, cyber and nuclear, will speak at an online event hosted by the Space Force Associations at 2 p.m. https://bit.ly/3e1nK2B

ICYMI

— The Hill: Treasury sanctions Iran’s ambassador to Iraq

— The Hill: Bipartisan group of senators call on Trump to sanction Russia over Navalny poisoning

— The Hill: House lawmakers call for continued assistance to Lebanon

— Washington Post: Virus shutdowns took a grim toll on amputee veterans who died by suicide, families say

— Washington Post: Our secret Taliban air force

— Reuters: Russia’s Putin says world has no future without arms control system

— Stars and Stripes: North Korea poised to test next US president with growing nuclear missile threat