WASHINGTON — Four and a half months is not long, but President Trump has accomplished an extraordinary amount in a short time. With shocking speed, he has wreaked havoc: hobbling our core alliances, jettisoning American values and abdicating United States leadership of the world. That’s a whole lot of winning — for Russia and China.

This work began promptly on Jan. 23, when the United States withdrew from the Trans-Pacific Partnership, leaving key allies empty-handed, fearful of the strategic benefit that will inevitably accrue to China. Then the secretary of state made plain that American values now take a back seat to security interests, even though those interests are enhanced by our partnerships with democracies that respect human rights and undermined by regimes that repress their citizens. Witness the brutal crackdown on opposition elements in Egypt and Bahrain after President Trump told their leaders that the United States no longer cares how they treat their people.

The president’s budget would slash funding for the United States Agency for International Development and the State Department by nearly 30 percent, rendering our embassies vulnerable to attack and shuttering vital programs that advance our interests. The budget would also starve the United Nations and its peacekeeping operations of essential support. This will condemn the United States to pariah status at this important, if flawed, institution, where our leadership has been unrivaled.

At NATO, the president’s reckless refusal to reaffirm our commitment to the defense of our allies under Article 5, while hectoring them publicly about their military spending, made our allies conclude they must go it alone. Nothing could have thrilled President Vladimir V. Putin of Russia more, or done more damage to the strength and unity of the Western world. And now the president has pulled the United States out of the Paris climate agreement, putting us at odds with virtually the entire world. Europe and China stand together on the Paris accord, while the United States is isolated.