Here's Donald Trump's endgame in Iran

The United States now appears at the cusp of a development scarcely conceivable just days ago: direct involvement in bombing Iran.

President Donald Trump has begun by dropping something else: hint after unsubtle hint that the U.S. might assist Israel in attacking unspecified targets in its conflict with Iran.

He's told people to flee the Iranian capital; posted an all-caps demand on social media for, "UNCONDITIONAL SURRENDER"; and said he knows where the supreme leader is hiding but won't kill him — for now.

The implied threat is obvious — that the U.S. could send its bombers and bunker-busters to burrow Iran's most secretive nuclear site, the mountain facility at Fordow, into oblivion.

There's also a longer-term threat that this conflict could keep escalating until it risks the survival, both literal and figurative, of the Iranian regime.

So what is Trump doing?

One clue came in an unusually long tweet from his vice-president. JD Vance specifically mentioned uranium enrichment: Iran can end it the easy way, he said, or the hard way, and, if it ends up being the latter, the U.S. military might help.

The prevailing consensus among experts interviewed by CBC News is that the current preferred option in Washington is non-participation.

That remains Plan A, in the view of a 34-year CIA veteran who spent a decade as the national intelligence manager for Iran at the Office of the Director of National Intelligence.

"It's clear the Trump administration would prefer to see a situation where Israel's attacks compel Iran to return to negotiations with serious concessions — driven by a desire to save the Islamic Republic," said Norman Roule, now a senior adviser at the Center for Strategic and International Studies think-tank in Washington.

"However, it's not yet clear if Iran's leaders believe their situation is so dire they must do so."

And that's why the U.S. government is actively seeking to instil a sense of desperation in Tehran, ramping up the pressure on Tuesday, said another analyst.

Kamran Bokhari predicted that Israel will hit increasingly vital infrastructure like communications, oil and water supplies.

It is also targeting hardline factions of Iran's security establishment — the Islamic Revolutionary Guard Corps and Basij — shifting the balance of power to the less-ideological, pre-revolutionary military.