Complex sentence: As they bought in to the future scenario of a war of Balkan inception, regardless of who started such a war, the alliance would respond nonetheless, it would view this conflict as a casus foederis; as a trigger for the alliance.
Split into simpler sentences: As they bought in to the future scenario of a war of Balkan inception, regardless of who started such a war, the alliance would respond nonetheless. It would view this conflict as a casus foederis; as a trigger for the alliance.