The United States is busy in the world, but no function seems more important than acting as the world’s universal comforter, constantly “reassuring” friends and allies no matter the location.

For instance, after Russia’s annexation of Crimea, the administration undertook what Secretary of State John Kerry termed “concrete steps to reassure our NATO allies.” The Military Times reported that Washington dispatched aircraft “to reassure NATO partners that border Russia.”

The process continues. The Wall Street Journal entitled an article “U.S. Tries to Help Ukraine, Reassure Allies Without Riling Russia.” Gen. Philip Breedlove said the transatlantic alliance would maintain new security measures throughout the year “to assure our allies of our complete commitment.”

Beijing’s assertiveness has resulted in another gaggle of friendly states clamoring for reassurance. Defense Secretary Chuck Hagel visited Asia in early April; the Washington Post reported that he sought “to reassure allies in Asia amid questions about U.S. commitment.” The president headed to Asia in mid-April, explained Voice of America, “in a bid to reassure allies in the region.”

As I point out in my new Forbes online column: “Washington’s obligation always is to give. The U.S. not only is supposed to guarantee the security of assorted friends and allies. It also must constantly reassure them. Americans must not only be prepared to die for anyone and everyone who wants protection, but Americans must always and in every way demonstrate that willingness.”

It’s a bizarre policy. First, the overriding responsibility of Washington officials is to safeguard America—its people, territory, constitutional liberties, and prosperity. The Department of Defense is not a charity created to protect the world, subsidize the improvident, calm the nervous, or save the indifferent.

Second, America’s broader foreign policies should be directed at advancing the interests of Americans. The national government is the agent of those who fund, staff, and support it, the American people. Their welfare is primary. Washington should look after their interests, not those of some imaginary “international community” that exists only in the minds of social engineers who desire to escape even minimal national restraints.

Moreover, the tendency of political organizations to live out Lord Acton’s famous warning that “power tends to corrupt and absolute power corrupts absolutely” requires the U.S. government to build limits into its own institutions and especially those beyond its borders.

The notion that America has an obligation to constantly “reassure” others is particularly pernicious when applied to the military. Washington’s principal obligation is to protect the American people, not those who desire to be defended by the world’s greatest military power.

There are occasions when it is in America’s interest to aid other states, but only rarely. Today Washington collects allies like most people accumulate Facebook friends.

Unfortunately, almost all U.S. allies expect to be defended by America rather than to help defend America. Some contribute small troop contingents to Washington’s unnecessary wars elsewhere, such as in Iraq, but that is not worth promising to face down nuclear-armed Russia on their behalf.

One of the worst consequences of America’s defense guarantees is discouraging prosperous and populous states from defending themselves. Europe has eight times Russia’s GDP—why is it relying on America at all?

Similarly, why is Japan, a wealthy state which until recently had the world’s second largest economy, expecting Washington’s help to assert control over contested islands? Why does South Korea, with 40 times the GDP of North Korea, presume the U.S. will forever maintain military forces in the peninsula?

Now Washington is sending Cabinet secretaries and military forces hither and yon to “reassure” these same nations that it will continue to subsidize their defense. Why should governments in Asia and Europe inconvenience their peoples when Washington is willing to burden Americans to pay for everyone’s defense?

It is time for Washington to start reassuring Americans.