Obama might have sent arms to Ukraine had he remained President for more than 2 years
Obama literally took the position that sending weapons was too provacative and might cause a violent Russian reaction. Oh wow. Look what happened.
Also many in the GOP caucuses in both houses supported Ukraine, such as Graham (and Darline appears to support) and McConnell, and thus countered Trump's bromance with Putin a bit.
Again, Trump very clearly and concretely put the maximal pressure on countering Russia in at least 12 if not 20 years. The Trump bromance with Putin is propaganda from the US establishment designed to be an explanation as to why the US military can't achieve its goals.