Ender, however, was unconcerned. As long as that monitor remained nestled in the back of his neck, he had nothing to fear from them.
Inserting monitors into children had become a common practice since the second “Bugger” invasion. When the insect-like aliens invaded the first time, humanity had just barely won; the second time, it was literally won by a happy accident, a brilliant general being in the right place at the right time.
Happy accidents do not happen twice, so the International Fleet started the Battle School. The more promising children of the monitor trials would go on to the school as young as six years old to be trained as future captains and generals.
Ender does have nothing to fear, until they remove the monitor and inform him that he’s been accepted at the School. To the officials at the School, he is more than promising; one could have as many well trained captains and generals as they liked, but in order to win a war against a higher-intelligence alien species, one would need an Alexander the Great. That’s just what Ender has the potential to be.
There’s only one problem: Ender may have the intelligence to keep the most well-educated adults on their toes, but when all’s said and done, he's still just a small child, and a very sensitive one at that.