Two days ago SoftBank CEO Masayoshi Son launched a heated attack on Dish Network's "incomplete and illusory" rival bid for Sprint, and now Dish chairman Charlie Ergen has fired back with shots of his own. In an interview with USA Today, Ergen sought to draw a line between his company and SoftBank by questioning whether the Japanese carrier has the ability to build a network on American soil.

"We are an American company, and the modernization of Sprint's network will have to be done from the U.S," said Ergen. "You have to climb the towers here, and you'll have to have U.S. employees who speak English. Operations command control will be in America. That's good for jobs. It doesn't mean that the other guys are bad. It's just that we have an advantage." Later, Ergen added "It's insulting to managers of Sprint to say that the only team that knows how to build a network is in Japan."

"If you have to lead tens of thousands of employees, culture matters," he said. "We're more culturally and geographically aligned with Sprint." Ergen also played on the issue of national security by noting US concerns over SoftBank's use of network equipment from Chinese manufacturer Huawei. "Spectrum is a national security issue," he said. "You want that network to be secure." Sprint and SoftBank have told US lawmakers that they will stop using Huawei equipment in any eventual deal.

As for what Ergen made of Son's calculations, which estimated that Dish's $25.5 billion offer for Sprint was worth just $6.31 a share next to SoftBank's $7.65-a-share $20.1 billion bid? "We're offering a higher price. That's just math." Ergen expects SoftBank to eventually raise its offer, calling Son's pledge not to do so "the biggest bluff of the day."