> getting rid of a prior member of an alliance undermines the very idea and value of the alliance
Not really. It does if one does this after they’re invaded, to evade mutual defence commitments. But acknowledging that there are no longer shared values and providing an off ramp is perfectly fine. Strengthening, even, as it shows heightened resolve to take the commitment seriously.
> not how must treaties work and certainly not how the NATO treaty is written
Most treaties have termination clauses. The North Atlantic Treaty’s Article 13 provides for voluntary exit [1]. (One could argue Ankara’s SS-4 purchase constitutes an Article 8 violation, though this would be petry.)
Treaties are about mutual understanding. If Americans and Czechs would find it unseemly to fight for Turkey’s defence in case of invasion, it does more harm to pretend they’re under collective defence than to amend the treaty to make it extremely clear whom one can invade without getting nuked and whom one cannot.
All this said, I think Turkey should remain a NATO member. They have shown themselves by arming Ukraine and denouncing Putin. They are a founding member. And their position remains strategically critical.
> how would Turkey's s400 purchase be an article 8 violation?
This has been covered in the American refusal to sell Ankara F-35s and ensuing sanctioning of it under CAATSA [1].
In short, no detection system is perfect. And no modern military system is sold without servicing. Letting Russia service an air defence system with the privilege of painting NATO jets, arms and missile defences is a breach of trust. It could be considered, again, pettily, though good luck to those who claims the law is often anything but, “an international engagement in conflict with” Turkey’s NATO obligations.
If any member gets booted out because of ideological differences, no matter the circumstances, other members will necessarily fear the same. This is extremely hard to avoid...
> member gets booted out because of ideological differences, no matter the circumstances, other members will necessarily fear the same
Ejection is a serious thing. Even its deliberation will have the effect you describe.
But anyone pretending NATO is immortal or immutable or above political alignment is naïve. If a member behaves radically differently from the others, will it be politically feasible to send one’s soldiers to their aid in a time of need? If the answer to that question isn’t predictably an unambiguous yes, the treaty should be modified. Leaving Russia to guess whether Estonia is a Britain member or a Hungary member undermines the alliance's deterrence.
These treaties were forged by our parents and grandparents. They’re stronger as living documents than relics.
Not really. It does if one does this after they’re invaded, to evade mutual defence commitments. But acknowledging that there are no longer shared values and providing an off ramp is perfectly fine. Strengthening, even, as it shows heightened resolve to take the commitment seriously.