"whoever, owing allegiance to the United States, levies war against them or adheres to their enemies, giving them aid and comfort within the United States or elsewhere, is guilty of treason and shall suffer death, or shall be imprisoned not less than five years and fined under this title but not less than $10,000; and shall be incapable of holding any office under the United States."
source US Constitution
Absolutely.
Hopefully a Canadian citizen will weigh in on this question - but I do not believe that Canada has a death penalty any longer. Whether there is an exception for this particular crime, or not, I do not know.***EDIT****Yes you can be executed for treason in Canada, its the one thing you can be executed for.
Treason
Louis Riel was convicted of treason and was hanged in Regina, Northwest Territories, on November 16, 1885. (Regina is now the capital of the Province of Saskatchewan.) Riel is the only person in Canada's history to have been executed for the crime of treason.
(in the US) Because they violate a statute which calls for a death penalty such as Murder - Rape - Treason - etc.
For high treason.
For treason i think
convicted and executed for treason
Michel Ney.
she was executed by Henry viii for treason
Any Roman citizen, including generals, charged with treason could be executed.
The old Lord of Cawdor was executed for treason, after betraying King Duncan of Scotland and attempting to overthrow him. His disloyalty and treachery led to his downfall and his title being given to Macbeth.
He murdered The Sheriff Of Lanark and burned down monasteries He was executed for treason.