He'd actually be more effective by trying to influence American public opinion to help the Ukrainians. With a population of 50m people, Ukraine doesn't need manpower - it needs American firepower and money. Similarly, Russia doesn't need you to sign up with them - you're be more effective helping to influence the US into *not* helping Ukraine with firepower and money.
“With a population of 50m people, Ukraine doesn’t need manpower - it needs American firepower and money.”
With a pop of 50 million, what they need is a will to stand up for themselves.
As events have shown, other than a few hundred radicals from the west of Ukraine, there isn’t much stomach, or support, for that.