I thought that they had some very serious ongoing disputes. Serious enough to shoot each other. But considering that the average Democrat voter couldn't find either Ukraine or Russia on an unlabeled (or often a labeled) map...
(From the low information voter's perspective, they are the same because they are both populated with "People who look kinda like Trump and have funny accents.")
NATO official position:
“All practical civilian and military cooperation under the NRC (NATO-Russia Council) with Russia was suspended in April 2014 in response to the Russia-Ukraine conflict.
At the Wales Summit in September 2014, NATO leaders condemned Russia’s military intervention in Ukraine and demanded that Russia comply with international law and its international obligations and responsibilities; end its illegal and illegitimate occupation ‘annexation’ of Crimea; refrain from aggressive actions against Ukraine; withdraw its troops; halt the flow of weapons, equipment, people and money across the border to the separatists; and stop fomenting tension along and across the Ukrainian border.”
The complaint against Manafort is that his political consulting in the Ukraine between 2004 - 2014 was to the Ukrainian president and later his party that are more closely aligned with Russia and Putin.
The United States wants to more closely align Ukraine with Europe, to keep the former Soviet republics from falling back into the orbit of Russia. (or direct control as is the case in Crimea right now)
Paul’s client was a pro-Russian Ukrainian.