Russia and Ukraine flashpoint

[SecondWar]

EpicRandy said:

Does lifting sanction against Russia requires congress approval or Donald Dump can do it on it own?
I feel like this is the sole true pressure US can apply to Ukraine as cutting support can be mitigated and will be mitigated through Europe increasing there own support.

Trump has been doing a fair bit the last few weeks that legally should have been approved by Congress first but he just did it anyway. He can’t be arrested and the Republican Congress would never impeach him so what exactly is going to stop him?