Trump names Robert O'Brien as national security adviser

• His appointment as Trump's fourth national security adviser comes a week after John Bolton's abrupt departure from the White House.
• The U.S., either on a diplomatic or military level, is currently engaged in conflicts with Iran, Venezuela, North Korea and Afghanistan.

Our thought bubble, via Axios' Margaret Talev and Alayna Treene: Trump thinks of O’Brien as a winner, because he has been successful at getting hostages released. He also looks the part — which has consistently been an important qualifier for the president.

• Trump leaned heavily on Mike Pompeo throughout the process of selecting a new national security adviser, and O'Brien is someone Pompeo has worked well with in the past.

Worth noting: O'Brien has previously worked for both Sen. Mitt Romney and George W. Bush, which could be a sticking point for Trump, who views both as symbolic of the GOP establishment.

• He's also viewed as far less hawkish than his predecessor — he is a hostage negotiator, after all — but that is a low bar given Bolton's aggressive tendencies.

Go deeper: Trump's anti-Iran strategy is facing its greatest test