I admit, I have been rather coy with Mister Nerva when it comes to the true nature of the obelisks. As a military man, the obelisks would naturally be more useful to him if they were some sort of weapon, and I have made sure to allude to that possibility from time to time.
It is not as though I am selling my gracious host a falsehood. After all, I have neither any proof that the obelisks could be weaponized, nor any evidence to the contrary. Their purpose is entirely theoretical at this stage, and if twisting those theories will convince Mister Nerva to march on the obelisks any sooner, then so be it.