It has been clear for a long time that President Trump is a person with a disorganized mind and a disordered personality. What the past few months and especially the past few weeks have brought into focus is how the president's pathologies have cascaded downward and outward through his administration. They have become institutionalized. The reason the administration so often does not act coherently is because it cannot. The world faces something new and baffling and frightening in Mr. Trump's second term: a psychotic state.

This does not mean that every individual in the government is emotionally or psychologically unstable. Nor is it a clinical diagnosis of the president himself. The issue is that the administration as a whole lacks a consistent attachment to reality and the ability to organize its thinking coherently. Mr. Trump's grandiosity, his impulsivity, inconsistency and his outright breaks with reality have become state policy.

It is the Iran war that has most vividly demonstrated the scope of the problem. In this conflict, the most potent antagonist has been the administration's own incoherence.

The Trump administration chose to wage a war without deciding on its aims, mapping out a strategy, planning for contingencies or even being able to explain itself. The goal was regime change—until it wasn't. The demand was unconditional surrender—until it wasn't. Deadlines were issued and then erased. Threats of total destruction were made and then pulled back. Iran's nuclear program was a casus belli in February despite that fact that we were told by Mr. Trump that it had been "obliterated" last June.

Normal administrations set up policy processes that assemble evidence from varied sources, collate viewpoints and priorities across multiple agencies and ensure rational deliberation before options reach the president.

In all those ways, the systematic review of policy amounts to an institutional mind: a cognitive process that organizes the government's deliberations to keep them rational and anchored in reality. In Mr. Trump's second term, those functions still exist, but they can be disrupted, circumvented or just plain abandoned at any moment on the say-so of the president and his senior officials.

When an agency goes haywire, the administration might rush to stabilize it. But until a coherent policy process is restored under a chief executive who understands the need for it, we should expect geysers of mindlessness to keep erupting in unforeseeable ways and places.

Institutional psychosis is ultimately self-defeating and unsustainable. Reality checks will return because reality always reasserts itself. But severe damage will have been done, damage that may take a generation or more to repair.