Will the US intervene militarily in the war between Israel and Iran, or will it stay out of it? This is the subject of worldwide speculation. US President Trump is leaving his decision open, but has announced"something big."

At the White House, US President Donald Trump was asked by journalists whether the US would attack Iranian nuclear facilities. Trump's response:"Maybe, maybe not—no one knows what I'll do. What I can say is: Iran is in big trouble."

And Trump explained that the Iranian side had contacted him and wanted to negotiate. He said it was very late for negotiations."There's a big difference between now and a week ago," Trump said. And then the US president announced that something big would happen next week, perhaps in less than a week.

Divided opinions on possible US involvement

Such statements by Trump, however, should not necessarily be understood as concrete announcements. Rather, they are a sign of: I'm not committing myself. Perhaps they are part of his strategy to put further pressure on Iran.

US politicians are divided over a possible use of the US military against Iranian nuclear facilities."If that's what's needed, I fully support it," Republican Representative Mike Lawler, for example, told NPR radio. The US could use bunker-busting bombs, which Israel doesn't have. The only fighter jets capable of dropping these bombs are the US B-2 stealth bombers.

But there are also warning voices—from both the Democratic and Republican sides. The US doesn't need another endless war in the Middle East. Israel is doing a good job of eliminating threats. The US should let Israel continue to do so, said Republican Representative Tim Burchette on CNN.

Iran's supreme leader warns against intervention

The question is what a possible direct US intervention might look like in concrete terms and how Iran would react. In a speech, Iran's Supreme Leader Ayatollah Ali Khamenei rejected Trump's demand for unconditional surrender and warned the US against intervention. Khamenei said this could cause irreparable damage.

Many in the US are deeply concerned that the more than 40,000 US troops in the region could be targeted for possible Iranian retaliation. BCA Research's chief geopolitical strategist, Marko Papic, explained on CNBC that the US could intervene directly, but limit it to a targeted strike."Attack a nuclear facility and then signal to Tehran: Look, that's it. I consider the matter closed. Let's negotiate now." In that case, it would be a major risk for Iran to respond by escalating the conflict, according to the strategist's assessment.

There is much speculation about the US's next steps. Whether Donald Trump has already made up his mind remains unclear, even after his recent statements.