Three former military officers are on the shortlist to replace former National Security Adviser Michael Flynn after his resignation, according to news reports.

Lt. Gen. Keith KelloggBackground: Kellogg is currently the interim national security adviser. The retired three-star general served as chief of staff of the National Security Council under Flynn. 

Baggage: During the Iraq War, he served as chief of staff for the Coalition Provisional Authority, which was responsible for setting up a government after the toppling of Saddam Hussein’s regime. The Coalition Provisional Authority was responsible for the purging of Baath party members from the government, which many blame for the rise of insurgents who would eventually join al-Qaida in Iraq, which would metastasize into the so-called Islamic State.

Also as someone who worked under Flynn and who is close to him, he could have to deal with Flynn’s baggage as well as his own.

Former CIA Director David PetraeusBackground: The most well-known of the potential replacements, Petraeus is a retired Army four-star general. He took command during some of the worst days during the war in Iraq and led the so-called “surge” strategy. He was the put in charge of United States Central Command before former President Barack Obama put him in charge in Afghanistan to replace Gen. Stanley McChrystal, with whom Flynn worked closely at Joint Special Operations Command. Obama would later appoint him to become director of the Central Intelligence Agency.

Baggage: Petraeus resigned from the CIA in disgrace after it was revealed he was having an affair with biographer Paula Broadwell. He also disclosed classified information to Broadwell, which led to him pleading guilty and serving two years’ probation and paying a $100,000 fine. He would still technically be under probation until April if he were tapped, according to CNN.

Retired Vice Admiral Robert HarwardBackground: Harward is a retired U.S. Navy SEAL who served as a deputy of Central Command under then-Gen. James Mattis, who is now President Donald Trump’s secretary of Defense. As CNN reported, Mattis had high praise for him, saying “He’s brilliant (for a SEAL, smile).”

Similarly, Tommy Vietor, former spokesman for the National Security Council for the Obama administration also tweeted praise for Harward.

Vice Adm Harward is a very impressive (and nice) guy. https://t.co/JYG9gzd1jr

— Tommy Vietor (@TVietor08) February 14, 2017

Baggage: Since his retirement, Harward has been a chief executive for Lockheed Martin UAE, based in the United Arab Emirates. If he is selected, it is possible his ties to the company that often does business with the United States military could come under intense scrutiny, as could his relations with the government in the UAE.