Why did Trump attack Iran? Nobody knows.

Early Saturday, the United States launched an open-ended war on Iran. And nobody really knows why.

For the past several weeks, the United States has been amassing forces in the area — with an estimated 40 to 50 percent of its entire deployable air fleet in the region. Throughout this time, the Trump administration has refused to give any kind of straightforward public justification for the buildup: a clear accounting of why they were considering war with Iran, what such a war would entail, or what victory would look like.

After the war began, President Donald Trump gave an eight-minute speech explaining why the war had begun. The speech ran through a series of grievances with the Iranian government: its anti-Americanism, its history of supporting terrorist groups, and its nuclear program (which he had previously claimed to have “completely obliterated” after airstrikes last year).

“For these reasons,” Trump said, “the United States military is undertaking a massive and ongoing operation to prevent this very wicked, radical dictatorship from threatening America and our core national security interests.”

This looks, from Trump’s description, to be a more open-ended military operation than his previous attacks on Iran. There is no specific defined singular objective, like setting back the nuclear program or killing an individual general. Instead, he speaks of a “massive” campaign dedicated to the broad goal of preventing Iran “from threatening America.”

But what does that mean? What is the real objective here, and how far is he willing to go to get there?

At first, Trump seemed to suggest that the war will focus on Iran’s military capabilities: that the US would “raze their missile industry to the ground,” “annihilate their navy,” and “ensure that Iran does not obtain a nuclear weapon.”

But later in the speech, he said the ultimate goal was regime change.

“To the great, proud people of Iran, I say tonight that the hour of your freedom is at hand,” he said. “When we are finished, take over your government. It will be yours to take.”

These objectives are fundamentally different.

Iran’s missile industry and nuclear program are not tools of domestic repression. If the goal is for the Iranian people to rise up, as Trump said, that would require a much more expansive military operation targeting Iran’s ground forces, including police and the Basij paramilitary involved in slaughtering thousands of peaceful protestors earlier this year. Most likely, a full toppling of the regime could not happen without some kind of ground invasion — and a significant one at that.

So which is it: a major bombing campaign targeting Iran’s military capabilities, or an even more expansive war of regime change? Or is Trump blustering, and a few days of bombing will give way to a climb down in which little ultimately changes?

It is literally impossible to say from Trump’s speech, or any other official communication from the US…