· In short: Britain's Foreign Secretary is concerned about the world entering a pre-war era

· David Cameron was particularly worried about Chinese expansion and any actions against Taiwan

· What's next? AUKUS submarines will be built by the UK, US and Australia

Former British prime minister David Cameron has warned the world is currently a "more dangerous" place than it has been for many years, citing conflicts around the globe and China's expansive plans, especially in relation to Taiwan.

"The lights on the global dashboard are flashing red, so it is a much more dangerous, difficult, uncertain world," Mr Cameron, who recently made a return to politics as British foreign secretary, told 7.30.

"We've not only got the situation in Europe with Putin's illegal invasion of Ukraine … we've also got the crisis between Israel and Gaza [and] more wars in Africa and Myanmar.

"So there is even more need for friendly countries with so much history … like Britain and Australia to work so closely together."

Mr Cameron wants them to do so, particularly against the backdrop of a more aggressive China.

Under the leadership of President Xi Jinping, China has routinely moved lines of demarcation on maps, been involved in border conflicts with India, been involved in conflicts in the South China Sea and curtailed individual freedoms and civil liberties in Hong Kong by introducing strict national security laws.

"We see China's approach today as a epoch-defining challenge," Mr Cameron said.

"We want to engage with China where we can … [on] things like climate change, but clearly, there are some very challenging aspects of its behaviour in Hong Kong  and when it comes to the treatment of Australia in recent years.

"We are seeing a much more assertive China and this only underlines the need for Britain, Australia and like-minded partners to work together."

China has also routinely conducted military sorties across the Taiwan Strait and spoken of the need for "reunification" with the self-ruled island.

It is this development that truly concerned the British foreign secretary, mere hours after the United States' top admiral of the Indo-Pacific command, John Aquilino, warned a house Armed Services Committee that China could invade Taiwan by 2027.

"We don't want to see any unilateral action to change the situation between China and Taiwan," Mr Cameron told 7.30.

"There's no doubt that were there to be something like a blockade it would have an absolutely calamitous effect, not just on Taiwan, but on the global economy.

"We've had recent evidence of a calamitous event with COVID.

"I think if that were to happen with Taiwan, it would be more significant."

Mr Cameron said the AUKUS military agreement between Australia, Britain and the US could be a key deterrent to Chinese ambitions in the region.

"We have the AUKUS agreement, which becomes very significant," he said.

"We do this not because of some sort of delusions of empire grandeur, we do it because the Indo Pacific is vital for the world's prosperity."

Mr Cameron said that despite the massive cost to Australia and the submarines not being expected to be ready until the 2040s, he believed the nation had acted in its best interests.

"Australia has rightly in my view bought into this idea and we'll spend what's necessary to deliver the submarines."

Israel needs clear plan to avoid Rafah casualties

In the Middle East, the war in Gaza continues and Mr Cameron has called on Israel to tread carefully with any offensive in Rafah, warning that mass civilian casualties could bring economic consequences.

"We're messaging very clearly to say you should not go ahead with that offensive unless you have a plan for how to protect civilians," he said.

"That plan doesn't exist at the moment.

"It's hard to see how you could carry out an offensive in Rafah without having a clear plan that's going to avoid an appalling level of civilian casualties."

Mr Cameron also called for a ceasefire so a new hostage swap could occur between Israel and Hamas militants.

He also said he wanted to see more Israeli aid flow into Gaza due to people, particularly children, starving there as the war drags on.

"They're [Israel] talking about flooding Gaza with aid, that isn't something they said before," Mr Cameron said.

"The number of trucks going in, in March so far, is radically up on the very low number in February.

"They're opening this maritime corridor, which is important in getting aid from Cyprus into Gaza.

"One of the things that I'd say about the maritime cargo, it's a good idea, but they should open the port of Ashdod.

"They can get really huge amounts of aid through that port and into Gaza."

Resolve Assange situation, says Cameron

Mr Cameron also said he would like to see Julian Assange potentially avoid being extradited to the United States.

"It would be good if we could see this resolved," Mr Cameron told 7.30.

"I think the legal processes need to be rolled through."

However, he did not absolve Assange of blame for his situation.

"Part of this is because Assange himself decided to camp in the Ecuadorian Embassy for years on end and that was unnecessary.