Such reasoning is predicated on the faulty assumption that the only alternatives are talking or shooting. Gone would be any chance of reconciliation. Instead of working out their problems, the ugly necessity of saving face, proving points, and winning popular sympathy would likely drive them further apart. Likewise, public debates in the UN intensify international tensions. By shouting their grievances at each other, countries allow their differences to assume a magnitude they would otherwise never have reached.
Quiet diplomacy is always more conducive to progress than diplomacy on the stage.
Nationalism fosters jealousy, suspicion, and hatred of other countries, which in turn raises the threat of war. This claim is based on the false premise that loving one's own country means hating all others. It makes as little sense as it would to maintain that a man who loves his own wife best hates all other women. Nationalism corresponds to the love a man bears for his wife and children. UN efforts help to eliminate such roots of war as hunger, poverty, ignorance, and disease.