Having said that, it is also wrong to steal from taxpayers to pay for other people's welfare -- which is what 80% of the federal budget consists of. (SS, Medicare, Medicaid, etc) Welfare harms both the people who pay for it and those who receive it. Theft is no more moral whether the recipient is your next door neighbor or across the world.
Therefore, swapping the <1% of our budget that goes to Ukraine with the 80% that pays for welfare would be a better use of money and make everyone better off.