Contrary to the view of this White House, we do not live in a zero-sum world. We live in a world where our security and prosperity are maximized when others enjoy the same. Today’s threats — terrorism, nuclear proliferation, disease, climate change, violent cartels — are not amenable to simple military solutions, nor can they be tackled by any one country acting alone. They require effective collective action, and thus, willing partners.

When the United States called after the Sept. 11 attacks, NATO answered, and for nearly 16 years the alliance has fought alongside us to defeat Al Qaeda and strengthen the Afghan government. Over 65 countries joined the fight against the Islamic State, and we rely on their enduring commitment to roll back terrorist havens. And when Russia illegally annexed Crimea and invaded Ukraine, the United States led the effort to impose sanctions on Russia.

It won’t be long before a fresh crisis arises. In 2014, I saw President Barack Obama successfully coax our allies to help contain and eradicate the Ebola outbreak in West Africa. If there is a flu pandemic that requires a similar coordinated international response, will our European friends heed President Trump’s call? Or if China takes aggressive action in the South China Sea, threatening our Asian allies as well as our own freedom of navigation, will our Western allies risk the economic repercussions of confronting China to stand beside an “America First” president who refuses to affirm our NATO commitments?

Our friends’ profound disappointment with the United States is a measure of the damage already done to America’s global standing by this administration.