But any attempt to alter the 2nd Amendment so you or I can't defend ourselves IS Treason.
Granted, it will destroy the country, because it will become a different country. But, that is perfectly allowed under the Constitution. Until 1865, the States believed that they could dissolve their bounds to the Union as the UK are likely to do tomorrow with respect to the EU. Only after the Civil War was the union deemed to be indissoluble. Most of the New England States considered just that during the War of 1812.
If changing an Amendment is Treason, then whomever is in power will defy the will of the people and convict for Treason anyone who supports a change to the Constitution that is not agreeable to the party in power.