Anthropic moved to close routes that allowed Chinese companies to access its models, including the use of subsidiaries registered in Singapore and connections through virtual private networks.
The operational detail is what matters. Export control over software doesn't enforce itself: somebody has to establish who is on the other end of the connection, which means corporate identity checks, traffic origin analysis, and judgement calls on ambiguous cases like the legitimate subsidiary of a multinational.
Each of those checks carries cost and an error rate. Block too aggressively and you turn away legitimate customers; too loosely and you fail the requirement. It's the dilemma of any automated filter, with regulatory consequences on one side and commercial ones on the other.
Context explains the urgency. In the same period, an open-weights Chinese model was competing with American ones, and the company had had one of its own models temporarily pulled over concerns tied to export control.
The structural irony holds: restricting access to a service does nothing about open-weights models, which travel by download and depend on nobody's server.