Major countries no longer need to declare or commit to full-scale war. They now engage other, lesser states to carry out their goals.
Consider Iraq, where we fund and equip Iraqis to fight ISIS for us.
Consider Syria, with all its complexities, where we choose various rebel groups to represent us against Assad and the Russians.
And now today, the UN acknowledges how bad things are in Yemen. They say famine is approaching there. Have they been watching before today? In Yemen we see another proxy war between Shia Iran and Sunni Saudi Arabia.
How convenient and sterile is the concept of proxy war!