Coalition frontbencher Andrew Hastie has declared anyone who thinks the rules-based order still exists is living in a “fantasyland”, amid an escalating US-Israel war on Iran, and as the government confirmed Australian troops in the region were safe after a weekend drone strike.

Australian troops posted at the defence force’s headquarters in the United Arab Emirates are all accounted for after a weekend drone strike, the federal government said, amid the growing conflict sparked by US and Israeli bombings in Iran.

The defence minister, Richard Marles, confirmed on Tuesday all Australian troops working at the Al Minhad airbase were uninjured in the strike, which came as Iran launched retaliatory attacks on nearby countries following strikes led by the US president, Donald Trump, and Israel’s prime minister, Benjamin Netanyahu.

“All the Australians who are there are safe and accounted for,” Marles said on Tuesday.

“We’ve got more than 100 personnel across the Middle East. Most of them are in the UAE where we’ve had an operational headquarters at Al Minhad for many, many years now.”

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It comes as the government defended the bombings, amid criticism from international law experts that the US and Israel had acted without legal authorisation.

Marles told ABC TV Iran had been seeking to acquire a nuclear weapon, which breached international non-proliferation agreements, but said it was a “matter for the United States and Israel to justify the legal side of their actions”.

“But there’s absolutely no doubt that the world could not trust Iran in terms of what it was doing with its nuclear program,” Marles said. “And it is utterly essential for global security that Iran be prevented from acquiring this capability.”

Liberal MP Andrew Hastie however dismissed those concerns about the international rules-based order, saying it was “nice to talk about” but irrelevant when Trump acted as an “apex opportunist” in the White House.

“I don’t think that exists any more, and anyone who says it does is living in a fantasyland. This is a new world order.

“I think the world is governed by power, and I prefer a powerful US re-establishing deterrence, rather than other countries like Russia, you know, using might to advance its national interest.”

But Hastie, an SAS veteran, warned war “is a very, very risky business” and said Iranians could be wondering if they are “trading one tyrant for another”.

“It’s a blunt instrument for regime change, which I think is part of Donald Trump’s strategy.

“I’m circumspect about regime change, having been involved in the wars of the last 15 to 20, years, and we’ll watch closely,” he said.

Australia has maintained a smaller force at Al Minhad airbase since the end of operations in Afghanistan. Last year, Defence said there were about 50 core ADF staff and a total of 70 to 80 Australians at the base at any time.

Known as HQME, the headquarters has supported ADF missions and contingencies since 2003.

Contingency planning to help the 115,000 Australians in the region is under way in Canberra, including moves to help thousands of travellers caught up in airline disruption.

The foreign affairs minister, Penny Wong, spoke with her counterpart in the UAE, Sheikh Abdullah bin Zayed Al Nahyan, on Tuesday.

He said the UAE was working hard to safely allow flights out of the country, and confirmed that Australians affected by travel disruptions in the UAE were being accommodated and provided with meals.

The Department of Foreign Affairs and Trade said it was working through thousands of registrations from the UAE and other countries to confirm the situation and welfare of Australian citizens, permanent residents and their dependants.