Peter, an issue tree is not a decision tree. The issue tree is about Understanding, neither more nor less. The decision tree people assume understanding, but 90% or more of decision making lies with understanding, so that is what I study. Issue trees do not make decisions, any more than writing makes decisions. Issue trees are just a form of writing, in which the relations between sentences are made clear.
Issue trees can make the debate clear, but they cannot resolve it. Only people can do that.