“Does that include inciting the citizens of that country?”
Why are you not asking that question of Putin and his regime’s Russian and Ukrainian provocateurs who have tried for years to subvert the Ukrainian government, the Ukrainian economy, and provoke a Ukrainian civil war as a pretext for a Russian conquest of the Ukraine nation whose territorial integrity Russian agreed to respect in exchange for Ukrainian surrender of the world’s third largest nuclear weapons force in the world?
How do you expect to be taken seriously when you object to a few U.S. Senators exercising their right of free speech in pursuit of their lawful duties which provide for guaranteeing Ukrainian territorial integrity; while you manifestly fail to note the overwhelming massive efforts of the Putin regime to overthrow the Ukrainian control of their own government, homes, and lives?
A “few U.S. Senators exercising their right of free speech” is vastly different from conducting foreign policy - exclusively the domain of the Executive.
In my opinion the duty is upon the Executive not the Legislative.