I understand you guys have uncommon rules for posting here, but as a professional microbiologist I have to input: Anthrax could never ‘wipe out all life on earth’ no matter how much of it anyone had. The title of this post is ridiculous hyperbole.

Bacillus anthracis is the bacterium that produces toxins that causes the disease, Anthrax. These toxins affect mammals, with a sub-100% fatality rate. The vast majority of life on earth I.e. other animals, insects, plants, bacteria etc. would be unaffected by exposure to these toxins.

Here’s a citation for a review paper if that helps: Spencer, Robert C. "Bacillus anthracis." Journal of clinical pathology 56.3 (2003): 182-187.

Although biological warfare has a history that goes back into ancient times, it is only a weapon that can be harnessed to its full, terrifying potential thanks to advances in modern technology. The proverbial infected cow catapulted into a city, or something poisonous dumped in the well all qualify as examples used for millennia, but it is the capabilities of bioengineering for improved mortality, and development of new and better ways to disperse the agents on the scale capable of massive, catastrophic (although see /u/01-__-10's rejoinder on scale) scales that is key to its modern form, and makes it one of many horrors wrought by the modern age.

The modern development of biological weapons is often seen as hand in hand with that of chemical warfare, and the origins can certainly be seen as stemming from the deployment in World War I, although biological agents were considerably less of a focus, and as a consequence, development in the post-war period remains generally a second fiddle to chemical agents. The USSR was, to a degree, an exception. Not having been targeted with large scale chemical warfare, but having experienced several epidemics in the period, there was a bit more appeal in pursuing bio agents.

The Military Chemical Agency was founded in 1925 under Yakov Fishman, part of their focus in that period on chemical and bio weapons development. The earliest biological programs were more focused on prevention and immunization, but few years later, research into biological agents also began, with a focus on the potential of weaponizing Bacillus anthracis and Clostridium botulinum, with study also conducted on the potential of Vibrio cholerae and Yersinia pestis (basically the bubonic plague). Headed by Nikolay N. Ginsburg in a laboratory in the Scientific Research Institute of Health, the group studied both how to increase the lethality of these as weapons, as well as how to improve their dispersal. Testing was certainly done on a variety of animals, but it is suspected that use of political prisoners as human test subjects may also have occurred.

Other programs also were formed by the early 1930s, with little to no cooperation at first as the system was so compartmentalized, but by the outbreak of WWII, a decent sized program with multiple institutes in multiple cities existed. While other nations had remained focused on chemical weapons, the USSR was likely second only to Japan by 1941 in the state of its offensive capabilities with bio agents, even though, as with signatories of the 1925 Geneva Protocol, they professed only to use them if provoked to it. None would be deployed during the war. However, while development had been a focus in the '30s, as with other fields, a number of figures fell victim in the purges of the '30s, including both Fishman and Ginsburg, although not all figures were killed, and instead kept at their work, just now under guard. Regardless though, it did stagnate the program for a time.

In the immediate post-war period, interestingly, information is fairly scant as compared to the pre-war program, in part because of the middling focus it received. Soviet era archives from this period which might have information remain unopened, and no significant figures involved in the program ever defected to offer a real glimpse. It is clear that the Soviets made use of information captured from the Japanese, who had developed a robust bio program in the '30s as well based principally in Manchuria, which the Soviets captured in '45, so it is safe to speculate that Japanese research impacted the Soviet program, especially with regards to Yersinia pestis, which the Japanese had focused extensively on. This was an important infusion into a program that had, while not going dormant, certainly slowed down.

The infusion kept the program alive, but didn't necessarily give it new legs, and with some minor exceptions, such as research into Botulinum toxin, very little progress in new improvements was evident over the next two decades. With the US scaling back its own program, and many Soviet military figures seeing no use for bio agents, USSR almost decided to end theirs, but instead, under the leadership of Yury A. Ovchinnikov, the program was given a major boost in the 1970s! Ovchinnikov pressed that new technological advances in recent years opened up new avenues of potential and was key for national defense. The irony is that Ovchinnikov's aim wasn't new bio weapons, it was just a desire to see more funding for biosciences, generally. A quote attributed to him is that:

At the Central Committee of the Communist Party, if we offer ten drugs nobody would support us. Nobody would give us money for medicine. But offer one weapon and you’ll get full support.

Simply put, he didn't want to necessarily make weapons, but knew that if he got the funding for that, the broader impact from investment would be a positive net-gain for all bio research. It certainly worked, directly resulting in the creation of the Shemyakin Institute, which far from focusing on bioweapons, had a large and robust program for biosciences generally. It was a deal with the devil though. Hand in hand with improved bioscience funding was the creation in 1974 of All-Union Science Production Association, the nominally civilian organization which would oversee the new bioweapons development moving forward, and better known as "Biopreparat". Although a total violation of the 1972 Biological Weapons Convention which the USSR ratified the following year, as the KGB asserted that the US had not shut down its own program in 1969 and thus was also in violation, they felt it justified. In any case, Biopreparat was publicly presented as a civilian research program, that was covered for a military research program into bioweapon defense, with its true, third level purpose kept top-secret.

Numerous facilities were created as part of Biopreparat. By 1986, 18 institutes were conducting research on bioweapons, and 14 plants existed to produce them or else could be mobilized to do so in the event of war. The program also employed somewhere between 40,000 to 65,000 people, and dwarfed any program implemented by another power. Although much of the research was on improving the lethality of existing agents such as anthrax, as well as what worked best under what conditions, weaponiztion of new agents was also a focus. One such example would be Marburg, a strain of Ebola (other strains also were researched), which was estimated to provide a mortality rate as high as 80 percent in some situations, as well as smallpox, a disease by that point essentially eradicated in the wild.

Although numbers are imprecise, based on the claims of Ken Alibek, who had been involved in Biopreparat as deputy director and later defected in 1992, the USSR maintained stockpiles of 100 tons of pathogens at various military airfields in the late Cold War for deployment, and if need be, could produce thousands of tons per year at existing facilities. US intelligence estimates place this as exaggerated, but only small amounts would be needed for catastrophic results, as only a few kgs, properly deployed, would easily kill thousands. Depending on the agent, such as in the case of botulinum toxin, even a portion of a kilogram is considered to be "militarily relevant" by experts. In any case, even using the lower estimates of the CIA and US military, pre-war mobilization would see the USSR ramping up production at 11 facilities as follows (with Alibek's numbers for comparison):

Although intelligence agencies of course new some of what was going on, and occasional defector reports helped flesh things out, the Soviets always denied the program existed, even while allowing portions of some facilities to be open to Western visitors as part of the cover. Several accidents, such as the Sverdlovsk outbreak which saw anthrax escape a facility (and was blamed on "tainted meat", saw periodic deaths from the program, and also provided small clues to the outside world, but despite accusations and pressure, denials continued. It was only after the fall of the USSR that, under Boris Yeltzin, Russia acknowledged the program existed, but insisted that they were going to be shutting it down. There isn't much reason to believe they followed through at that time, and the state of it since then is not appropriate for this venue, although suffice to say it is telling that the government position only a few years later had been to walked back the admissions under Yeltzin.

Cieslak, Theodore J., and Eitzen, Edward M., Jr. “Clinical and Epidemiologic Principles of anthrax.(National Symposium on Medical and Public Health Response to Bioterrorism, Feb. 16-17, 1999, Arlington, Virginia).” Emerging Infectious Diseases 5, no. 4 (July 1, 1999): 552–555.

Hoffman, David E., Dead Hand. Anchor Books, 2009.

Leitenberg, Milton & Raymond A. Zilinskas. The Soviet Biological Weapons: Program A History. Harvard University Press, 2012.

I can talk a little bit about Stepnogorsk and biological weapons facilities specifically in Kazakhstan.

First, the Soviet bioweapons program was known as "Biopreparat", which was largely a way for the USSR to present plausible deniability for the development of biological weapons (the USSR was one of the signatories of the Biological Weapons Convention in 1972, and so Biopreparat was ostensibily "civilian" research). There were a number of Biopreparat facilities scattered across the USSR, with a major laboratory center outside of Moscow, and a number of production plants - most infamously was one in Sverdlovsk (modern-day Yekaterinburg) that had an accidental release of anthrax spores in 1979, causing at least 100 deaths.

After the Sverdlovsk accident, a new anthrax facility was established in 1981 in Stepnogorsk, which is a small town in Akmola oblast in Kazakhstan (nowadays that means its near Kazakhstan's capital, but at the time this was effectively nowhere important). The facility was nominally attacked to the Progress Scientific and Production Association, which was a civilian outside manufacturing fertilizer and pesticides (no one in the civilian organization or even locally resident in the town actually worked in the weapons facilities). The facility was put under the management of Ken Alibek (an ethnic Kazakh biologist), who had orders to manufacture a "battle strain" of anthrax, known as Anthrax 836 - this involved fermentation, drying, milling, centrifuges, and machinery to load the strain into spray tanks and bomblets, and then shipped by truck to railheads or airfields for Soviet military usage and storage (work was also done with other diseases, such as glanders, tularemia and plague). The Stepnogorsk facilities were heavily secured, and stripped of all surrounding vegetation. Ultimately it had a capacity to produce 300 tons of anthrax a year. According to Alibek, the total Soviet military capacity was supposed to be 5,000 tons, but this wasn't reached in actuality. In any case, Stepnogorsk wasn't the biggest-capacity production facility - one in Kurgan was supposed to be able to produce a thousand tons, and one in Penza five hundred tons). At the very least there seem to also have been production facilities at Berdsk and Omutninsk, as well as one under the direction of the Ministry of Agriculture at Pokrov).

With all that noted, the facilities were not always run at capacity, or even that efficiently. Biological weapons are living agents after all, and can be incredibly fickle to produce and store - there were whole production lines that ended up producing no usable agents. In any case, Alibek ultimately moved to the main Biopreparat lab in Koltsovo, outside Moscow, in 1987 and became the program's First Deputy Director in 1988.

Alibek ultimately defected to the US in 1992, so American weapons experts had a pretty good understanding, based on his information, about what the Biopreparat program was capable of and where its facilities were located. A team of biological weapons experts first visited the Stepnogorsk site in June 1995 (this was a follow-up project to Project Sapphire, which had seen over 1,300 pounds of highly-enriched uranium transported from Kazakhstan to Oak Ridge in the US). The team came at the invitation of the Kazakh government and was there to inspect whether the facilities were being shut down per the agreement of the Russian government under Yeltsin.

Gennady Lepyoshkin, a former Soviet colonel, had taken over direction of the plant from Alibek in 1987 and was still managing it - he told the team to get lost. Stepnogorsk was a mostly ethnic Russian community, and if anything they and the facility didn't consider themselves accountable to the Kazakhstani government. After much haggling and arguing, the team finally gained access to inspect the facilities, and ultimately Lepyoshkin and his staff opened up.

The team ultimately also gained access to the bioweapons testing grounds, which were located on Vozrozhdeniye (Renaissance) Island, once an island in the middle of the Aral Sea, now part of the dried up seabed (the testing facilities on the "island" are technically in Uzbekistan). The first bioweapons facilities had been established there in 1936, but tests were ended the following year, and not restarted until 1952. A testing complex was on the southern end of the island, and a military airport and military settlement with a few hundred troops and their families on the northern end. The site was closed in late 1991, and this is where a lot of bioweapons material was found - often improperly stored and leaking. The other bioweapons facilities located in Kazakhstan were the Scientific Research Agricultural Institute in Gvardeysky (Zhambyl Province) and the Anti-Plague Scientific Research Institute in Alma-Ata (Almaty).

In any case, the governments of Kazakhstan and Uzbekistan had no use for these facilities or their weapons, and were very much interested in having them cleaned up and closed, or converted to civilian uses. The Cooperative Threat Reduction Program is a program that the US runs to assist former Soviet countries in cleaning up and securing WMD sites. To that end, the Stepnogorsk facility was dismantled and converted to civilian use with the assistance of American specialists and funds in 1997-1998, and Vozrozheniye Island was cleaned up with the cooperation of the Uzbekistani government in 2002.

I'm confining myself to just discussing facilities in Central Asia, as opposed to the Soviet program as a whole. I'll also defer to a specialist to describe the history of the American program. The most I will say on the subject is an anecdote too good to pass up. Nixon unilaterally shut the American bioweapons program down in 1969, because with nuclear weapons he didn't see the need or the point of biological weapons, going so far as to say "if someone uses germs on us, we'll nuke em".

Edit: as far as 2000 in Stepnogorsk goes, there was actually an international scientific conference held there in July 2000 ("Biotechnology Development in Kazakhstan: Non-proliferation, Conversion and Invesment"), that included tours of the facilities being dismantled.

Sources:

David Hoffman. The Dead Hand: The Untold Story of the Cold War Arms Race and its Dangerous Legacy

McLeish, Caitríona. “Opening up the Secret City of Stepnogorsk: Biological Weapons in the Former Soviet Union.” Area, vol. 42, no. 1, 2010, pp. 60–69. via JSTOR

More detailed discussion of the Kazakhstani bioweapons sites and their conversion is Gulbarshyn Bozheyeva, Yerlan Kunakbayev and Dastan Yeleukenov. "Former Soviet Biological Weapons Facilities in Kazakhstan: Past, Present, and Future." Available here

I've just finished reading several books on the biological and chemical warfare research and development in the US and the USSR. If you are interested, here they are. Take the book written by Ken Alibek with a grain of salt, he's a Soviet defector and has been accused of exaggerating.

Biohazard: The Chilling True Story of the Largest Covert Biological Weapons Program in the World--Told from Inside by the Man Who Ran It

A Higher Form of Killing: The Secret History of Chemical and Biological Warfare

Stalin's Secret Weapon: The Origins of Soviet Biological Warfare

I have just started Lab 257: The Disturbing Story of the Government's Secret Germ Laboratory but I've gotten sidetracked by the newest book about Chernobyl.

You should also try books about Operation Paperclip. At the end of the second World War, the US and the USSR engaged in a stealthy, fast-paced race to scoop up all of Germany and Japan's most talented scientists, ignore any human rights violations they may have committed, and integrate them into areas of governmental scientific research. While the most famous was our "acquisition" of Wernher von Braun, the inventor of the German V-2 rocket, who helped the US win the space race as well as working on military applications like the development of ICBMs, we got chemical and biowarfare experts too. Both the Soviets and the US benefitted from the research Germany had been doing on chemical and biological warfare. They also benefitted from the research Japan was doing on both chemical and biological warfare, but quite frankly, I don't have the stomach to read an entire book about what Japan was doing, what I know already is more than enough. The US in particular scooped up Japanese chemical and biowarfare experts (war criminals).

There's not as much information about the US development of biological weapons, mainly because when the US and the USSR agreed to stop biowarfare offensive research, well, they did. The Soviets never stopped, and if the attacks on Russian journalists are any indication, they may have continued even after the cold war ended. The UK dabbled in a bit before the ban as well.

If you want to know some specifics of anthrax, you can read about the anthrax outbreak in Sverdlovsk (now Yekaterinburg) 1979. Sverdlosk was a closed city that had a bioweapons manufacturing plant. Among their productions was weaponized anthrax. One day, a staff member removed a filter from a vent in the anthrax production section, it was being troublesome. He didn't have time to put a new one in, so he just noted in the paperwork that a filter was needed before the next shift started up their production. This notation was missed, so hours went by with no filter to protect the city from stray weaponized anthrax spores. Oops. Suddenly, downwind, people started getting anthrax, including the deadliest form, inhalational. According to Wikipedia and the Soviets, 100 people died, but I'm not sure that's a number we can trust. The Soviets blamed it on tainted black market meat, but nobody was buying that cover. Anthrax: The Investigation of a Deadly Outbreak covers this incident well.

Hopefully, that helps, I can try to answer specific questions if you have them.