Pakistan has dozens of laboratories and production and storage sites scattered across the country. After developing warheads with highly enriched uranium, it has more recently tried to do the same with more-powerful and compact plutonium.

The $52.6 billion U.S. intelligence arsenal is aimed mainly at unambiguous adversaries, including al-Qaida, North Korea and Iran. But top-secret budget documents reveal an equally intense focus on one purported ally: Pakistan.

As digital communications have multiplied, and NSA capabilities with them, the agency has shifted resources from surveillance of individual targets to the acquisition of communications on a planetary scale.

True net-heads sometimes resort to punctuation cartoons to get around the absence of inflection.

No one can keep track of how many people use Internet, how many machines it can reach, or even how many sub- and sub-sub-networks form a part of it.

CloudShield did not see itself as a cloak-and-dagger company. It made its name for high-end hardware that could peer deeply into Internet traffic and pull out and analyze 'packets' of data as they flew by.

In computer circles, any unencrypted data is known as 'cleartext.'

Snowden grants that NSA employees by and large believe in their mission and trust the agency to handle the secrets it takes from ordinary people - deliberately, in the case of bulk records collection, and 'incidentally,' when the content of American phone calls and e-mails are swept into NSA systems along with foreign targets.

For months, Obama administration officials attacked Snowden's motives and said the work of the NSA was distorted by selective leaks and misinterpretations.

The NSA's business is 'information dominance,' the use of other people's secrets to shape events.

Snowden is an orderly thinker, with an engineer's approach to problem-solving.

Most people inside the bureau believe that the blown opportunities to head off 9/11 would not recur today. Even among the FBI's doubters, few disagree that the bureau has come a long way.

On average, since 9/11, the FBI reckons that just over 100,000 terrorism leads each year have come over the transom. Analysts and agents designate them as immediate, priority or routine, but the bureau says every one is covered.

A national security letter cannot be used to authorize eavesdropping or to read the contents of e-mail. But it does permit investigators to trace revealing paths through the private affairs of a modern digital citizen.

In late 2003, the Bush administration reversed a long-standing policy requiring agents to destroy their files on innocent American citizens, companies and residents when investigations closed.

If Iraq had succeeded in spray-drying anthrax spores to extend their life and lethality, that would have been among the most important secrets of its wide-ranging weapons program.

The defection of Hussein Kamel was a turning point in the U.N.-imposed disarmament of Iraq in the 1990s.

Of all Iraq's rocket scientists, none drew warier scrutiny abroad than Modher Sadeq-Saba Tamimi.

The modern era of continuity planning began under President Ronald Reagan.

For a decade, makers of AIDS medicines had rejected the idea of lowering prices in poor countries for fear of eroding profits in rich ones. The position required a balancing act, because the companies had to deflect attacks on the global reach of their patents, which granted exclusive marketing rights for antiretroviral drugs.

In 1995, Glaxo bought Burroughs Wellcome and became the presumptive leader in AIDS therapy.

In Africa through the 1990s, with notable exceptions in Senegal and Uganda, nearly all the ruling powers denied they had a problem with AIDS.

Drug manufacturers could afford to sell AIDS drugs in Africa at virtually any discount. The companies said they did not do so because Africa lacked the requisite infrastructure.

The first and pivotal negotiations over global access to AIDS drugs began in Geneva in 1991. They lasted two years, but confidential minutes suggest they were doomed the first day.