After reading AT&T's massive argument (PDF) for why the government should allow it to purchase T-Mobile, you might wonder just why AT&T wants the smaller company at all. And you might have a few questions about AT&T's own network, which the company says will shortly be under severe capacity constraints that its rivals won't face.

The whole document is a rather amusing exercise in making both AT&T and T-Mobile look like underdogs in a field of unbeatable competitors. Actual quote from AT&T: "With sharply declining prices, dazzling innovation, soaring output, enormous product differentiation, new entr[ies], and fierce advertising, the intensity of the competition in the US wireless marketplace is extraordinary."

And here is AT&T's own description of the company it plans to buy for $39 billion:

"T-Mobile is not an important factor in AT&T’s competitive decision-making."

"As a standalone company, however, T-Mobile USA would continue to face substantial commercial and spectrum-related challenges. It confronts increased competition from industry mavericks such as MetroPCS, Leap, and others; its percentage of US subscribers has been falling for nearly two years; and it has no clear path to LTE."

"T-Mobile USA, in contrast to others, does not have a differentiated network position. T-Mobile USA has admitted that it suffered from its late transition to a 3G network, and unlike Sprint, which first promoted a 4G network, T-Mobile USA’s HSPA+ launch appears to have been lost among other carriers’ 4G messaging."

"AT&T does not believe that T-Mobile USA has a particularly compelling portfolio of smartphone offerings as compared to AT&T, Verizon, and Sprint."

"To the extent that T-Mobile USA’s prices are lower than those received by AT&T and Verizon Wireless for otherwise comparable subscribers, T-Mobile USA’s lower prices have not stimulated growth in its share of retail subscribers. This indicates that other aspects of T-Mobile USA’s service are in some way lacking."

And it's not just T-Mobile; AT&T can't say enough bad things about the imminent problems with its own network:

"AT&T’s network-capacity challenges, however, are not just 'looming' a few years down the road—they are here today, the product of AT&T’s mobile broadband leadership and its need to support multiple generations of services. And although other providers’ public statements indicate that they have sufficient capacity to cover their needs until additional spectrum is made available via auction several years from now, AT&T must move more quickly."

"In many markets where T-Mobile USA has spectrum, AT&T’s capacity constraints also prevent it from dedicating enough spectrum to launch LTE, deploy it optimally, or meet expected demand. For example, in [Redacted by AT&T], AT&T lacks spectrum to deploy LTE at all."

"From a consumer’s perspective, the capacity constraints confronting these companies, if unaddressed, would translate into more dropped and blocked calls, slower speeds, and access to fewer and less advanced applications."

Finally, AT&T's competitors are unbelievably powerful, awesome companies. They are, quite probably, run by gods living among us mortals. (Also, in case regulators didn't notice it in the many other statements on the matter, T-Mobile continues to be non-mavericky and sucktacular.)

"Verizon Wireless is the nation’s largest wireless provider with a leading reputation for high-quality network performance, and it competes with AT&T in almost every local market. It has an exceedingly robust spectrum position Verizon Wireless often targets AT&T in its commercials and asserts that Verizon’s network is superior to AT&T’s more congested counterpart."

"Sprint has reversed recent trends and, in 2010, achieved successes that CEO Dan Hesse called 'unprecedented in the history of the U.S. wireless industry' Sprint’s success contrasts sharply with T-Mobile USA’s own recent performance. Second, Sprint has achieved this early 4G success in part because of its exceptional spectrum position, which is far stronger than AT&T’s today."

"MetroPCS and Leap have now become the industry’s leading 'maverick[s],' a term that does not apply to providers that, like T-Mobile USA, are losing share Indeed, MetroPCS and Leap are now mentioned in the same breath with AT&T, Verizon Wireless, Sprint, and T-Mobile USA. And in a growing number of markets, these providers—and MetroPCS in particular—are estimated to have surpassed T-Mobile USA."

US Cellular is a "highly successful provider" that, according to AT&T’s internal estimates, "has double-digit and sometimes leading shares of many markets in which T-Mobile USA and AT&T also compete."

After dozens of pages of this, one starts to wonder just how AT&T and T-Mobile executives manage to tie their own shoelaces.

The rhetorical move here is an obvious one: play up competition in the wireless market, make AT&T appear to be in imminent peril without the acquisition, and show that AT&T isn't buying out a rival. There is some truth underlying the points made by AT&T here, but it does raise the question of why AT&T wants to acquire T-Mobile at all.

The company provides a host of reasons, but two are key: AT&T wants more spectrum, and more towers from which to utilize that spectrum. T-Mobile has both, and it already uses GSM technology throughout its network, as does AT&T. AT&T could just save its $39 billion and put up more towers of its own, but this is easier said than done; indeed, by buying T-Mobile, AT&T gets eight years of tower building at once. As AT&T describes the process:

To add a site, a provider must locate a suitable and available location, arrange to acquire the site through purchase or lease, comply with regulatory requirements that necessitate extensive studies and consultation, apply for and obtain building permits and zoning approvals, contract with third-party vendors to purchase the needed equipment, construct the site and associated backhaul, and then integrate the site into the network. This process can literally take years. In the San Francisco/Bay Area market, for example, the zoning process alone—only a single step in this long, multi-step process—has taken AT&T an average of [Begin Confidential Information] [End Confidential Information] to complete The T-Mobile USA sites that AT&T could integrate represent more than eight years of new sites based on AT&T’s 2010 rate.

The trick for federal regulators is to look beyond the over-the-top sob story AT&T is selling and weigh the arguments on their merits. Opposition has been fierce, even from groups like CCIA, a DC trade group that actually counts T-Mobile among its members.

"The proposal is stunningly brazen," said CCIA today. "To combat their weak case, AT&T is mounting a massive lobbying and PR effort. Their aim is to convince key decision makers, and those they listen to, of the absurd proposition that having fewer choices of wireless carriers will not lead to less price, service and innovation competition."