From the dusty helicopter window the ground looked like any number of other tropical war zones; the bombed-out buildings, the charred palm trees, the burnt-out abandoned vehicle.

Then there was the glint of the green lagoon and suddenly I was looking at the same unmistakable terrain — the inlets of water, the long, sandy spits that I had been gazing at for weeks on a map in London as I tried to imagine what it meant to be inside the no-fire zone.

It was four years since I had been to Sri Lanka and everything had changed. The shaky ceasefire, which was collapsing even then, had imploded with an all-out military offensive to drive out the Tamil Tigers.

At a distance I was not necessarily opposed. In five years of covering South Asia I had travelled several times to “Tigerland” and was in no doubt of the rebels’ capacity for brutality.

The first story I filed from Sri Lanka was about how the Tigers were abusing the freedom of movement granted to them by the soon-to-be-formalised ceasefire to cross into government territory and abduct children. When I travelled to Killinochi in the same visit I was accompanied by a teenage soldier wearing a cyanide capsule round his neck.

The helicopter banked sharply at the top of lagoon and began to fly south. There, laid out below, was the no-fire zone. You could not hear the gasps above the noise of the helicopter blades but you could see the jaws of the passengers fall open. I gazed at a beach of white sand on to a scene of devastation.

I saw this same coast north of Mullaitivu soon after the Boxing Day tsunami in 2004. The devastation this time was far worse. I had come from the Manik Farm camp where the escapees from this beach had told me their stories of living under the shelling. Sometimes seeing is the only believing.

It looked as if a giant had got into his car and driven over paper tents. The tarpaulins — many draped over hastily dug bunkers, as later became apparent upon close examination of digital photographs — were packed, sheltering 100,000 people in the 3 sq km zone.

It was difficult to try to imagine the terror of being trapped here, between the guns of the Tamil Tigers and the Sri Lankan Army’s battle to the end.

It was later, looking at the video footage and photographs that I and others captured from the helicopter that the details began to emerge. As quickly as I spotted one crater I saw another. And another.

And another. Then what appeared to be graves. I was out of my depth. I sent the photographs to military and photographic experts and asked what they showed.

The Sri Lanka I returned to last week is a changed place. Sources who had been outspoken have become cowed and frightened. Some have fled the country.

A government official begged me not to write anything harmful to national interests because the Government would “take [it] out on minorities”, of which he is a member. The newspapers that once charmed with their amusing idioms now resemble something printed in North Korea.

Sri Lanka has won its war against the Tamil Tigers. The hope is that its citizens can live without fear of terrorist attacks. I fear that they have paid a high price and lost something precious in the process.

Visible from the helicopter were the mounds on the beach where Father Amalraj, a Catholic priest, said that his parishioners were buried after he blessed their burnt, bloodied bodies. I hope that the truth will not rot there too.

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