PHNOM PENH — The costs of the border war between Thailand and Cambodia are cruelly obvious in the hospital in Mongkol Borei, a breezy, low-rise complex surrounded by trees.

Wounded soldiers lie quietly on their beds. One man, his arm amputated from the elbow, has his wife sitting with him, smiling and trying to encourage him. The wife and child of another sit on a mat next to his bed.

Anaesthetist Sar Chanraksmey's hands are shaking, and tears rim his eyes, as he shows me graphic images on his phone of the terrible blast injuries he has treated.

"My heart aches," he says. "Please tell the world we just want peace."

This second round of fighting between the two armies in less than six months has lasted longer than the five-day war in July, and been a lot more destructive.

There have been artillery exchanges all along the 800km (500-mile) border, and intense close-quarter battles between Thai and Cambodian soldiers for control of a few forested hilltops.

The Thai air force has had a free hand bombing targets inside Cambodia, which has limited air defences and no air force of its own to speak of.

Cambodia's feared BM21 rockets, an inherently inaccurate weapon, have rained down on the Thai side of the border, killing a civilian and injuring others, despite an early evacuation by the authorities.

Cambodia does not publish the number of soldiers killed since hostilities resumed on 7 December, but the Thai military estimates that it might be several hundred.

On the Thai side, 21 soldiers have died. This discrepancy is a testament to the much larger and better equipped armed forces that Thailand has.

As in July, it is difficult to work out exactly why the 120-year-old dispute over small strips of territory has erupted into such a large-scale armed conflict.

Thailand has blamed Cambodian forces for an ambush of a team of Thai engineers on 7 December, in which two soldiers were injured. The Cambodian government accuses Thai Prime Minister Anutin Charnvirakul of restarting the war to boost his prospects in the coming general election.

What is different this time is the determination of the Thai military to keep fighting until, in the words of its commanders, the Cambodian army no longer poses a threat on the border. It has rejected Cambodian calls for a ceasefire, and even snubbed President's Trump's appeal to both sides to call a truce.

The line you hear in conversations with Thai military officers is that Cambodia cannot be trusted to honour a ceasefire unless it has suffered much bigger losses than it did in July.

The twisted steel and gaping hole in the road bridge which crosses the Me Teuk river in Pursat province offer vivid evidence of that tough approach.

On 13 December Thai F-16 jets dropped several bombs, tearing out a 20-metre section of the Chinese-built bridge, which links a long strip of Cambodia's southern border with Thailand to the rest of the country. They also struck an eight-storey building next to a casino, which the Thais say was being used as a military command post.

The unintended, or perhaps intended, consequence of this was to prompt an exodus of Chinese men and women, who we saw pulling roller suitcases and clutching computers and screens as they made their way noisily across the river on the old steel bridge, which is still intact but unsuitable for heavy vehicles.

The officials who escorted us to the bridge explained, without much conviction, that they had been working in an upstream hydroelectric power station; but their clothing, and the equipment they were carrying, made it near certain they had come from one of the scam compounds which operate in many of Cambodia's border areas. They covered their faces and would not speak to us.

The association of the Cambodian leadership with the scam industry is a weak point in the country's battle for international sympathy, and Thailand has made targeting it a core part of its military campaign, bombing several casino complexes.

The Cambodian government says it is now taking action against scam centres, but their proliferation in the country in recent years, and their link to a number of very powerful, politically-connected Cambodian figures, raises doubts about how sincere that action is.

Where the Cambodian government hopes it can win sympathy is in its pleas for peace. Its almost constant refrain since the fighting restarted has been an appeal to return to the July ceasefire, and for international mediation. In Cambodian cities, signs in English and Khmer proclaim its desire for peace – one echoed by almost every Cambodian you meet.

There are good reasons for this. Aside from the terrible punishment its soldiers are getting on the front lines, the impact on the economy must be severe, although statistics on this are hard to come by.

More than 700,000 migrant workers have come back from Thailand, nervous of possible hostility among the public there. Some 480,000 Cambodians have been uprooted from their homes, and panic over real or just rumoured Thai air strikes has forced many families to move more than once.

The $5bn (£3.7bn) border trade with Thailand has stopped. Border communities in both countries are being hurt. And the increasingly global push against online fraud, with the US and UK among others recently sanctioning several Cambodian tycoons, threatens a scam industry which, by some estimates, accounts for more than half the national economy.

But since President Trump's decisive intervention to stop the fighting in July, attitudes in Thailand have hardened towards its smaller neighbour.

The shock of seeing a political crisis, one which brought down a Thai government, deliberately ignited by Hun Sen, the veteran leader who wields decisive influence in Cambodia, and who leaked a private phone conversation with the then Thai prime minister, has soured the public mood. As did compelling evidence that Cambodian soldiers were still laying landmines during the ceasefire which have left seven Thai soldiers with amputated limbs.

Efforts by President Trump and Malaysian prime minister Anwar Ibrahim to revive the earlier ceasefire have been met with a firm refusal by the Thai prime minister. "We don't have to listen to anyone," he said.

A restaurant owner in Surin, on the Thai side of the border, told us how different this conflict is from the brief war 14 years ago.

There have always been close links between people in Surin, where many speak Khmer, and those on the Cambodian side. Many Cambodians work there.

Back in 2011 she said there was no public animosity towards them, and they stayed in Thailand throughout the fighting. This time she said there was much more suspicion of the Cambodians, and most of them left. She put this down to the incendiary comments on social media, which have whipped up an angry and distorted nationalism in both countries.

That makes it difficult for leaders on either side to be seen to be conciliatory, especially in Thailand, where, thanks to the crisis caused by Hun Sen's leak, an election will take place next February. None of the parties contesting the election is supporting a ceasefire.

Thailand accuses Cambodia, with its calls for outside intervention, of playing the victim. Cambodia accuses Thailand of acting the bully. These are not new stereotypes, but they have been amplified so much this year it is hard to see where the trust that is essential for restoring their relations can be found. — BBC