There is an argument that sectarian conflicts should play out without outside interference. By definition such conflicts rise out of mouldering, unresolved disputes. What is the alternative to letting these proceedings run their course? The sectarian issues will not likely go away but may well be enlarged and amplified because outside interests and ambitions have insinuated themselves.
Indeed, this process of escalation has continued several times into global confrontations.
If pustules have the potential to sort themselves locally this is almost always the best solution.
However horrific, local carnage is preferable to global carnage.