When the tests were reported, in the pre-Internet era, we in India only had access to what the Indian media published. And they were toeing the official line that the tests went off very well and yielded more than satisfactory results.
Luckily, we now have access to the archives of several newspapers abroad and can find out what they had reported on the blasts in May 1998. Not because the ‘foreign’ version is always correct or more accurate. Just that it provides us with one more viewpoint, free of patriotic biases.
The New York Times, dated May 15, 1998,( just 4 days after the blast) carried a report that expressed anxiety that the monitors had picked up only 1 out of the 5 blasts. Presuming that India’s claims were right, the writer’s first conclusion was that the thousands of seismometers around the world had failed to detect the tests, landing a body blow to the international monitoring system set up as part of the Comprehensive Test Ban Treaty. Now countries could conduct tests surreptitiously, secure in the knowledge that they will escape detection.
But later in the article, the author realizes that there could be other reasons why the tests were not detected. He writes:
..Given the lack of independent evidence, the rest of the world only has India's word about the size and scope of most of the announced blasts, or even whether they took place at all.
Certainly India already seems to be exaggerating its achievement. Estimates by Indian seismologists of the explosive energy of Monday's large blast are more than double those of American experts.
For the Monday series, India said one was a ''thermonuclear device,'' meaning it had more force than an atom bomb. And it said the tests on Wednesday were in the ''sub-kiloton range,'' meaning they had a force of less than 1,000 tons of high explosive.
A bizarre twist, given that India and Pakistan are old foes, is that the best seismic data on the Indian blast came from a seismometer in Pakistan, 435 miles from the Indian test site.
The seismogram of a Monday blast, held a hint of what was perhaps another blast signature.
The clue is a tiny ripple in the flat line of the tracing before it zigs and zags wildly as energy from the blast was received and recorded. That tiny blip, he said, might have been caused by an earthquake or a small bomb detonated just before the big one.
…The energy of the large blast appeared to be equal to about 25,000 tons of high explosive, or about half of what Indian scientists have claimed.
This tallies with Mr Santhanam's estimate of the intensity of the blast.