Emperor Cartagia had agreed to allow the Shadows to occupy the island of Selini as a base in exchange for elevating him to "godhood." Mollari protested this action, with the knowledge that the Vorlons were destroying entire planets that had been "touched" by the Shadows at that time.
After Cartagia's assassination, Mollari ordered the entire island of Selini mined with nuclear warheads. Most of the island's Centauri population was evacuated during the night, but enough residents stayed so that the Shadows would not notice anything was amiss.
Shortly before the Vorlons were expected to arrive at Centauri Prime, Mollari detonated the warheads, thereby removing the last vestiges of Shadow influence on the planet. However, Mollari failed to notice that he himself had also been touched by the Shadows, and the Vorlons continued to advance. Just before the Vorlons could fire their planet killer, their forces were called away to a larger battle, sparing Centauri Prime.
Because of the actions that Mollari took in destroying Selini, the Drakh, servants of the Shadows, wreaked havoc on the Centauri Republic. By implanting Regent Milo Virini with a Keeper, the Drakh instigated open conflict in late 2262 between the Interstellar Alliance and the Republic. A combined Narn and Drazi fleet eventually bombarded Centauri Prime, and the Drakh threatened to detonate nuclear weapons they had planted themselves across the planet. The specter of escalating destruction forced Mollari to accept a Keeper of his own, and to allow control of the Republic by the Drakh for years to come.