A compromise will probably be reached in the coming future whereby India earns a waiver from the US’ CAATSA sanctions per the National Defense Authorization Act of 2019’s clause that this is possible if it either reduces its overall purchase of Russian weaponry or cooperates with America on other issues critical to its strategic interests.
India will be on a slippery slope once it agrees to discuss with the US its defence relationship with Russia on a case-by-case basis. It will be an affront to India’s sovereignty and self-respect to allow the US to have a say in its relations with Russia.
So long as the nuclear balance between Pakistan and India can be maintained, then a conventional military peace between the two Great Powers is assured, but the disruption of this equilibrium is dangerous for the entire world because of the encouragement that this could give either state to launch a first strike.
If the U.S. does not keep its promises and continue supporting the Kurds, the Turkey’s contract for the purchase of Russia’s S-400 will remain in force. If the Kurds leave Manbij and other areas specified by Ankara, Turkey will receive American anti-missile systems, sacrificing relations with Moscow.