Concisely revise it in simple english :    Two factors facilitated the emergence of health as a security issue. The first of
 these was the growing acceptance during the 1990s of a broadened security
 agenda. The end of the Cold War saw security analysts shift their focus away
 from threats, especially military threats, to more diffuse risks. This opened the
 door for a more eclectic range of issues to be considered as security concerns.
 Further, the shift from threat to risk allowed security’s focus to shift from the
 idea of a ‘clear and present danger’ to more probabilistic assessments of
 potential hazards. Both of these moves opened up a space whereby public
 health issues could be raised as security concerns. Moreover, questions were
 raised not only over the security agenda – those issues which were to be
 considered as security concerns – but also over the referent object: whose
 security was to be protected? Whereas the Cold War had prioritized national
 security, in the post-Cold War world global and human security began to be
 considered as legitimate concerns. Although definitions of human security
 varied, the very idea that risks to the individual from macro-level developments
 could be part of the security agenda again allowed a space for the inclusion of
 health as a security issue. After all, individuals generally were more likely to be
 at risk from new infectious diseases spread as a consequence of globalization
 than from ethnic conflict, environmental disasters or terrorism  The second facilitating factor was human agency. A number of prominent
 individuals used their positions of power and influence to place health on the
 foreign and security policy agenda. Two examples of this are the former head
 of the World Health Organization, Gro Harlem Brundtland and President
 Clinton’s ambassador to the UN, Richard Holbrooke. As WHO’s Director
 General, Brundtland emphasized the changing nature of public health in a
 globalized world, and argued that global public health could not be divorced
 from broader social and political trends. Significantly it was during Brundtland’s
 tenure that WHO coined the term ‘global health security’. 
The second example of individual agency is that of Richard Holbrooke, who
 is widely acknowledged as a key player in the securitization of HIV/AIDS.
 According to Barnett and Prins (2006: 360), when visiting Africa in 1999
 Holbrooke realized not only the scale of the HIV/AIDS pandemic but also that
 existing aid-based approaches were failing to deal with the crisis. Moreover the
 potential social consequences of the pandemic were beginning to become
 apparent, including state instability. On his return to New York, Holbrooke
 was instrumental in placing HIV/AIDS on the Security Council’s agenda.
 What is unclear is whether Holbrooke saw his actions as motivated solely by
 security concerns, or whether he saw the securitization of HIV/AIDS as a way
 of achieving greater political prominence and global action to help deal with
 the crisis. This potential for the securitization of health to act as a Trojan Horse
 for greater attention and assistance to the most needy is an important theme
 in the debate over health and security.
 Neither the broadening of the security agenda nor individual agency
 however can explain the emergence of health as a security issue. If it was simply
 a by-product of the broadening agenda, then this move would have been expected in the early to mid-1990s when the broadened agenda was being
 developed, not the late 1990s/early twenty-first century when it did eventually
 appear. And agents cannot act successfully without issues of substance with
 which to make their case. Rather three substantive health issues contributed to
 the emergence of health on the security agenda: the spread of infectious disease;
 the HIV/AIDS pandemic; and bioterrorism. Moreover, these three issues
 continue to dominate the thinking of security analysts with regard to health,
 though not necessarily public health specialists.