No, that's not a spelling mistake. Nationism is the term to use for those who believe that it is all right to use extortion and initiate violence against people of a different nationality. It's the national equivalent of the racial term racism. Why isn't this word even being used in popular language? Nationalism is a different thing, although it is also "bad".
Did you ever wonder why our "democratic" ruling class come down so hard on racism while they almost glorify nationism? Well, obviously nationism is helping them pay their bills. It's in their interests to be blind to the logical inconsistency in their philosophy. It would seem that if racism is bad, then nationism should also be bad, right? But instead we have the UN and Olympic eurocrats (and wannabes) extorting taxpayers' money to fund their propaganda wars. And the Australian government imprisoning refugees.
The vision about nations that we should strive for is that there should be no nations. Ignore them, and we can hope, they will go away. All people should be free to move and trade anywhere in the world in peace. In other words, we should work for "personal sovereignty" and against "national sovereignty".