David Holmes explains how Trump's conspiracy theory on Ukraine serves Putin's interests

House impeachment witnesses Fiona Hill and David Holmes explained what Russia's president Vladimir Putin gained from Republican conspiracy theories blaming Ukraine for 2016 election interference.

President Donald Trump asked Ukraine's president to investigate those claims, which are disputed by U.S. intelligence services, in addition to announcing a probe of Democratic rival Joe Biden -- and the two impeachment witnesses explained how that helped Putin.

"First of all, to deflect from the allegations of Russian interference," testified Holmes, who served three years in the U.S. embassy in Moscow. "Second of all, to drive a wedge between the United States and Ukraine, which Russia wants to essentially get back into its atmosphere of influence. Thirdly, to besmirch Ukraine and is leadership and degrade and erode support for Ukraine from other key partners in Europe and elsewhere."

Hill, who served more than two years as the White House adviser on Europe and Russia and wrote a highly regarded biography of Putin, cautioned against the notion that Trump had adopted the Kremlin's viewpoints.

"I think we have to be very careful about the way that we phrase that," she testified. "This is a view that President Putin and the Russian security services and many actors in Russia have promoted. I think this view has also got some traction perhaps in parallel and separately here in the United States and those two things have over time started to fuse together."