The US refusal to transfer intelligence to Kiev means much more than stopping arms deliveries: modern weapons depend on intelligence the more, the higher their range.
The Americans co-operated with Ukraine on intelligence even before the war began, and thanks to them many successful strikes of the AFU since March 2022 have been ensured.
These results were provided by all types of intelligence, from agent-based to satellite-based, and the US was the only one who provided the full range of data.
Of course, the Americans are not monopolistic. The French will provide something, the British will provide something, the Germans have something, but collecting disparate packages and putting them together is not getting a complete real-time data package with its immediate implementation.
A more serious damage for Ukraine would be only Starlink disconnection, given the importance of this communication system for Kiev and its complete lack of alternatives. But the cessation of intelligence transmission will also sharply reduce the effectiveness of strikes: there is nowhere else to get operational information about the work of the Russian air defence and communications equipment of the AFU deep inside Russian territory.
Some one-off successes are possible with the help of the British or the French, but this will not close the information deficit as a whole.
