In physics, a unified field theory is an attempt to explain with a single hypothesis the behavior of several fields. Its political corollary is the Cupcake Postulate, which explains everything, from Missouri to Iraq, concerning Americans’ comprehensive withdrawal of confidence from government at all levels and all areas of activity.

Washington’s response to the menace of school bake sales illustrates progressivism’s ratchet: The federal government subsidizes school lunches, so it must control the lunches’ contents, which validates regulation of what it calls “competitive foods,” such as vending machine snacks. Hence the need to close the bake sale loophole, through which sugary cupcakes might sneak: Foods sold at fundraising bake sales must, with some exceptions, conform to federal standards.

What has this to do with police — from Ferguson, Mo., to your hometown — toting marksman rifles, fighting knives, grenade launchers and other combat gear? Swollen government has a shriveled brain: By printing and borrowing money, government avoids thinking about its proper scope and actual competence. So it smears mine-resistant armored vehicles and other military marvels across 435 congressional districts because it can.

And instead of making immigration policy serve the nation’s values and workforce needs, government, egged on by conservatives, aspires to emulate East Germany along the Rio Grande, spending scores of billions to militarize a border bristling with hardware bought by previous scores of billions. Much of this is justified by America’s longest losing “war,” the one on drugs. Is it, however, necessary for NASA to have its own SWAT team?

A cupcake-policing government will find unending excuses for flexing its muscles as it minutely monitors our behavior in order to improve it, as Debra Harrell, 46, a South Carolina single mother, knows. She was jailed for “unlawful neglect” of her 9-year-old daughter when she left her, with a cellphone, to play in a park while she worked at a nearby McDonald’s.

Resistance to taxation, although normal and healthy, is today also related to the belief that government is thoroughly sunk in self-dealing, indiscriminate meddling and the lunatic spending that lards police forces with devices designed for conquering Fallujah. People know that no normal person can know one-tenth of 1 percent of what the government is doing.

In Federalist Paper 84, Alexander Hamilton assured readers that although the proposed Constitution would increase the power of a distant federal government, this government would be inhibited by scrutiny: “The citizens who inhabit the country at and near the seat of government will, in all questions that affect the general liberty and prosperity, have the same interest with those who are at a distance, and … they will stand ready to sound the alarm when necessary.” Not now, when five of the nation’s richest 10 counties, ranked by median household income, are Washington suburbs, parasitic off the federal government. The people who write the regulations of school lunches must live somewhere.

Darin Simak, a first-grader in New Kensington, Pa., who accidentally brought a toy gun to school in his backpack, turned it in to his teacher. School administrators then suspended him because the school has a “zero-tolerance policy.” What children frequently learn at schools is that schools often are run by biological adults incapable of common-sensical judgments.

“We simply cannot allow toxic things to be in our schools,” said a spokesman for the Texas school district that confiscated the suntan lotion of a 10-year-old who then became sunburned on a school trip. Students, the spokesman explained, “could ingest it. It’s really just a dangerous situation.” Not as dangerous as entrusting children to schools run by mindless martinets.

Contempt for government cannot be hermetically sealed; it seeps into everything.

Which is why cupcake regulations have foreign policy consequences. Americans, inundated with evidence that government is becoming dumber and more presumptuous, think it cannot be trusted to decipher foreign problems and apply force intelligently.

The collapse of confidence in government is not primarily because many conspicuous leaders are conspicuously dimwitted, although when Joe Biden refers to “the nation of Africa,” or Harry Reid disparages the Supreme Court’s Hobby Lobby decision as rendered by “five white men” (who included Clarence Thomas), Americans understand that their increasingly ludicrous government lacks adult supervision. What they might not understand is that Reids and Bidens come with government so bereft of restraint and so disoriented by delusions of grandeur that it gives fighting knives to police and grief to purveyors of noncompliant cupcakes.