“and the secession of a State from the Union is a direct disposition of the Territory of the United States”
That is the part you made up. If a state leaves the union it is no longer the territory of the United States. I see it differently than you do. I think it is ludicrous to expect a state that wants to leave the union to have to get everybody else’s permission to go their own way. Since the constitution does not mention secession, and since the 10th Amendment says powers not granted to the federal government by the Constitution, nor prohibited to the States, are reserved to the States or the people, I believe that is where the power to secede lies and states should be able to leave the union as they wish with or without the federal government’s blessing.
“If a state leaves the union it is no longer the territory of the United States.”
That is pure nonsense. You cannot just unilaterally, arbitrarily, and prejudicially abrogate the Engagement the State with its ratification entered into the joinder of territories with the other States in the perpetual Union. Proposing such a state of affairs involving unilateral secession of the State is nothing less than lawlessness, alienation of the State, and treasonous rebellion prejudicing the rights and duties of the member States of the perpetual Union. To regain or recover the sovereign powers the State previously delegated to the perpetual Union of the United States, the State must obtain the consent of the Congress assembled and the member States of the perpetual Union. Only when the State has lawfully recovered the sovereign power it delegated to the perpetual Union can the State lawfully withdraw from the Engagement it previously made and proceed on to secede as a sovereign state with all of its sovereign powers recovered from the former joinder with the other States of the perpetual Union. Until that occurs, the territory of the State is cojoined with the Territory of the perpetual Union of the United States as with any delegation of sovereign powers to the joint sovereign nation.
“I think it is ludicrous to expect a state that wants to leave the union to have to get everybody else’s permission to go their own way.”
Actually, the coastal states could secede and land lock the remaining states eventually destroying them with a trade/travel embargo.
This is why russian is not allowing Ukraine to secede. It is because russia would be landlocked except for the Pacific ocean route.
For example, CA, OR and WA plus TX, OK MO, IL, WI, and MN could pretty much completly land lock a bunch of state via secession.