Kurt Volker's former advisers testify before impeachment probe

Former National Security Council staffer Catherine Croft and Ukraine expert Christopher Anderson testified before House impeachment committees Wednesday.

Why it matters: Croft and Anderson are former advisers to Kurt Volker, the former U.S. envoy to Ukraine, who was named in the whistleblower complaint about the July 25 presidential phone call that spurred an impeachment inquiry into President Trump.

The big picture: House committees leading the impeachment inquiry believe that the president's decision to withhold military aid to Ukraine and his push for Ukraine to investigate his 2020 rival Joe Biden jeopardized national security.

• Trump says he withheld aid to force other European nations to contribute and argues that calling for Ukraine to investigate the Bidens was appropriate.
• Anderson's testimony fills in more blanks on how high-level diplomats like Volker navigated White House strategy on Ukraine.
• Croft's testimony fills in more blanks on former U.S. Ambassador to Ukraine Marie Yovanovitch's ouster, which the whistleblower said was one of the circumstances that led him to believe Trump may have been soliciting foreign election interference.

What they're saying:

1. In his opening statement, Anderson said "there were some vague discussions" in a June 18 meeting at the Department of Energy about how to address Trump lawyer Rudy Giuliani's "continued calls for a corruption investigation."

• Anderson said that after the meeting, he "agreed on the importance of not calling for any specific investigations" with Bill Taylor, the top U.S. diplomat to Ukraine.
• Per Anderson's testimony, during a June 13 meeting with Volker and former national security adviser John Bolton, Bolton cautioned that Giuliani was a "key voice with the President on Ukraine, which could be an obstacle to increased White House engagement" with the country.

Background: Taylor testified that Trump conditioned the release of military aid on the Ukrainian president's willingness to investigate the Bidens' ties to natural gas company Burisma and the 2016 election. He told EU Ambassador Gordon Sondland on Sept. 9: "I think it's crazy to withhold security assistance for help with a political campaign."

2. In her opening statement, Croft said lobbyist and former Rep. Robert Livingston told her in multiple calls that Yovanovitch — who served under President George W. Bush — was an "Obama holdover" associated with George Soros and "should be fired."

• "It was not clear to me at the time — or now — at whose direction or at whose expense Mr. Livingston was seeking the removal of Ambassador Yovanovitch," Croft added, saying she sent documentation of the calls to Trump's former Russia adviser Fiona Hill.

Background, per the NYT: House investigators are determining if smears against Yovanovitch — largely by Giuliani — were "part of a larger pressure campaign" by Trump and his lawyer "to secure from Ukraine politically beneficial investigations into Democrats."

Go deeper: John Bolton has been asked to testify in impeachment probe