It’s considered adult to want to maintain a failing global empire and press for endless war. Only children want peace and friendly relations among nations. From Doug Bandow at theamericanconservative.com:
A new book tour by H.R. McMaster shows how little the foreign policy professionals have learned from two decades of endless war.

When President Donald Trump took office, his aides promised there would always be adults in the room. Especially when it came to foreign policy, learned, stable professionals would ensure responsible and intelligent actions.
Except the adults turned out to be idiots. They fought the president at every turn when he sought to withdraw from endless wars. They insisted that Washington remain allied to the worst of the worst, supporting the vile Saudi regime in its aggressive and murderous war against Yemen. They urged policies that treated Russia as a permanent enemy. They backed American dominance of every existing alliance and relationship, infantilizing America’s friends and maximizing Washington’s obligations.
For instance, McMaster recently charged that Tehran, a political, economic, and military wreck, has “hegemonic designs.” He made this claim after serving at the center of foreign policymaking in the world’s dominant power which is determined to be the global hegemon in control of every region on earth, essentially imposing the Monroe Doctrine on every continent. Supportive policymakers insist that the U.S. should intervene everywhere while no one else can intervene anywhere. Indeed, in their view America is entitled to meddle at any time for any reason.