Biological warfare is considered by Israeli security officials to be one of the most dangerous forms of unconventional attacks, and an Israeli bio-defense program has taken shape in recent decades with the growing threat of bio-terrorism backed by rogue regimes. "I will say that Israel has the best solution to this threat in the world," Giora Eiland, former head of the National Security Council, told The Jerusalem Post on Sunday. "I can say with certainty that Israel has prepared a series of steps designed to deal with biological warfare." Eiland said Israel had invested heavily in the field of bio-terrorism but added that the threat remained "huge." "A bio-weapon can be dispersed in a hall full of people and the consequences would only be felt a week later," he warned. "This is unlike a chemical attack, which would be felt immediately. The swine flu [that has broken out in Mexico and, apparently, other countries] helps illustrate the threat of bio-weapons." The bio-defense program Eiland alluded to was not always in place - it took the defense establishment decades to develop it. In 1948, barely three years after the trauma of mass extermination in the Holocaust and a few months before Israel declared independence, David Ben-Gurion sent a letter to a Jewish Agency representative in Europe, calling on him locate Jewish scientists who could "either increase the capacity to kill masses or to cure masses; both things are important." A new unit to study biological warfare was established in 1948 under the auspices of the IDF's Science Corps, thanks to lobbying efforts by Hebrew University molecular biologist Alexander Kenyan. By the early 1950s, the Science Corps had dissolved into a network of civilian-run research institutes affiliated with the Defense Ministry, one of which was the Ness Ziona-based Israel Institute for Biological Research (IIBR). The IIBR was tasked with preparing solutions to the threat of biological warfare, but reportedly faced severe budgetary constraints in the decades following its creation, causing it to seek funding from commercial ventures. The turning point came in 1991, when Saddam Hussein's Scud missiles rained down on Israel and security officials found themselves wholly unprepared for the possibility of unconventional warheads. From the early 1990s onwards, the IIBR was provided with large budgets aimed at constructing an adequate bio-defense program. Today, the biological threat against Israel stems from a combination of terrorist groups and rogue regimes such as Iran, which the US government suspects of experimenting with biological weapons based on ricin and smallpox, and Syria, which has also been accused of operating a bio-weapons program. In recent years, Israel has acknowledged that groups hostile to the state have the motivation to carry out bio-terror attacks, and the increased threat prompted the Defense Ministry to establish a new bio-defense research program at the Home Front Command's headquarters in Ramle last year. Dr. Tzvika Doshnitzky, formally head of the Nuclear-Biological-Chemical Branch of the IDF's Medical Corps, has described biological terrorism as the most dangerous of threats because of the difficulty involved in immediately determining that an attack has taken place. In a paper titled "Biological terrorism is alive and kicking," which was published in February in the Israeli journal The Medical, Doshnitzky and two other scientists stressed that early detection was key to addressing a biological attack. "In the past three decades," they wrote, "we have witnessed an increase in attempts by terrorist organizations to use biological warfare materials differently from the way they are used by states." They added that the 2001 anthrax letter attacks in the US were a global turning point for bio-defense programs, and noted that the US had since allocated $1.5 billion for bio-terrorism research. In Israel, a controversial anthrax vaccine trial called Omer 2 took place between 1998 and 2006, using 716 soldier volunteers. Afterwards, a number of participants complained of breathing problems and skin conditions, and some have since sued the Defense Ministry.