Option 1 would lead to less bloodshed.
Why is that?
Realpolitik concerns prompted the development of the Central and Entente alliances.
Crab, I cannot think of an example in which ideology was ever completely removed from the equation. The way states and their leaders frame "the nation's interests and aims" inevitable occurs through an ideological filter. Bismarck's
Realpolitik operated to unify the Germanies into a Prussian-led Empire and sought to position that Empire atop Europe. That aim of national predominance is absolutely ideological. So too were Kissinger's diplomatic gymnastics, designed as they were to maintain US hegemony in an environment of multiple crises.
"Realism" in international relations theory aggravates me in the same way that people describing their beliefs as "rational" drives me up a wall. Advocates of a particular theory of statecraft, a theory naturally built on an underlying set of assumptions which can be traced to a particular
ideology, have cornered the market on a word which suggests that all alternatives are "unrealistic." In the same way, people who describe their beliefs as "rational" imply that anyone who disagree within is
irrational, or in other words, insane.
A much more intriguing question would be, "which ideological assumptions should form the basis of [US] foreign policy?" Then we could really figure out what people believe.