I doubt there's any government in the world that guides itself primarily by strategy or conceptual documents or worldview. Anybody who has the reins of power has to look at practical limitations and tradeoffs - the fact that you can focus at most on one or two things at a time, that resources are limited.

Snowden has yet to tell me anything that was a fact that I have been able to rebut or that anybody in the U.S. government I have talked to has been able to rebut.

Daniel Ellsberg showed tremendous courage back in the '70s.

Snowden has been very sparing about discussing his early life or his personal life.

The surveillance of ordinary people is far greater than I would have imagined and far greater than the American public has been able to debate.

Cheney was among the best secretaries of defence the country has ever had. He was a very effective White House chief of staff. He did not make many enemies, and he had the ability to persuade people with that soft tone and very reasonable style of his. He's always been exceptionally good as the right-hand man.

I don't think Cheney started off in 2000 with a burning desire to become vice-president. I think the prospect gradually became more appealing, and he goosed the process.

The funny thing is that Dick Cheney has done more than anybody in the White House for quite a long time to throw up roadblocks against future historians.

No one ought to be under any illusion that Cheney privately thinks himself a failure.

Ecuador has never stated flatly that it would give asylum to Edward Snowden.

There's a long history of private-company cooperation with the NSA that dates back to at least the 1970s.

The first reports of AIDS closely followed the inauguration of President Ronald Reagan, whose 'family values' agenda and alliance with Christian conservatives associated AIDS with deviance and sin.

Early in 1986, the World Health Organization in Geneva still regarded AIDS as an ailment of the promiscuous few.

Throughout the early and mid-1990s, the Clinton administration debated the merits of paying for AIDS testing and counseling of vulnerable populations overseas.

In the wealthy industrialized nations, effective drug therapies against AIDS became available - AZT as early as 1987, then combinations of antiretroviral agents in 1996. The new drugs offered hope that fatal complications might be staved off and AIDS rendered a chronic condition.

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.

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.

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

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

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.

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

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

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

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.

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.

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.

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.

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.

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

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

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

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.

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

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.

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.

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

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.

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.

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.

Pakistan has accepted some security training from the CIA, but U.S. export restrictions and Pakistani suspicions have prevented the two countries from sharing the most sophisticated technology for safeguarding nuclear components.

U.S. surveillance of Pakistan extends far beyond its nuclear program. There are several references in the black budget to expanding U.S. scrutiny of chemical and biological laboratories.

Stuxnet, a computer worm reportedly developed by the United States and Israel that destroyed Iranian nuclear centrifuges in attacks in 2009 and 2010, is often cited as the most dramatic use of a cyber weapon.

China and Russia are regarded as the most formidable cyber threats.

The Obama administration has provided almost no public information about the NSA's compliance record.

There is no reliable way to calculate from the number of recorded compliance issues how many Americans have had their communications improperly collected, stored or distributed by the NSA.

The causes and severity of NSA infractions vary widely. One in 10 incidents is attributed to a typographical error in which an analyst enters an incorrect query and retrieves data about U.S phone calls or emails.

The NSA has different reporting requirements for each branch of government and each of its legal authorities.

At Cheney's initiative, the United States stripped terror suspects of long-established rights under domestic and international law, building a new legal edifice under exclusive White House ownership.

By now, you've heard endless warnings about the risk of short, trivial passwords. There's a good chance you ignore them.

Even complex passwords are getting easy to break if they're too short. That's because today's inexpensive computer chips have the power of supercomputers from the year 2000.