It would be wrong to say the United States is trapped in the war it started. It has options. But it is now going to pay a very steep price, no matter which of them it chooses. It can desist in Iran " having demonstrated, for no good reason, that its military is far less dominant than the world had assumed. Or it can draw resources from theaters that are of vital national interest, such as Europe and East Asia, to fund what the president refers to as his Iranian "excursion." Or it can resort to the extreme military options Mr. Trump darkly alluded to in social media posts starting in early April, which will redound to the everlasting shame of the country he leads. The United States stands to lose its reputation, its friends or its soul.