The exact process that the military uses to declare a DEFCON increase is not perfectly-understood by the public. It is usually assumed that an upgrade in military preparedness is made by the Joint Chiefs of Staff (the highest commanders in the American military) with the approval of the president. However, some anecdotal evidence suggests that top-level military leaders are able to increase the DEFCON level without the president — for instance, some sources report that the Strategic Air Command's decision to issue a DEFCON 2 during the Cuban Missile Crisis occurred without input from President Kennedy. Note again that the precise actions that the military takes at each DEFCON level are, for obvious reasons, kept secret. Thus, most of the information that the general public has on the DEFCON scale is based on old declassified documents or historical DEFCON "spikes" revealed to the public after the fact. Though some non-military, non-government sources may claim to know the current DEFCON level, there is no way to verify this. The DEFCON scale is not the only measure that the US government and military use to rate their readiness against external and internal dangers. These include LERTCON (used by the US and NATO allies), REDCON (used by individual US military units), and more. However, the most important alert scale besides DEFCON is likely the EMERGCON scale. These conditions (which have never been issued before) are thought to be issued in the event of nuclear war and include civilian directives as well as military ones. EMERGCON has two levels, which are:  Defense Emergency: Made in the event of major hostile attacks against U.S. or allied forces overseas. Issued by unified commander or higher authority.  Air Defense Emergency: Made in the event of attacks against the US, Canada, or military installations in Greenland. Issued by the Commander in Chief of the North American Aerospace Defense Command.  Note that, by definition, all military forces go to DEFCON 1 in the event of an EMERGCON being issued. Though much of the DEFCON scale's history is kept secret for obvious reasons, the declassified information that is available to the public is fascinating in its own right. Conceived in the late 1950s as a means of coordinating NORAD defense efforts between the U.S. and Canada, the DEFCON system has gone through several changes between its creation and its current form today. For instance, the original DEFCON scale had "sub-categories" for several DEFCON levels: "Charlie" and "Delta" under DEFCON 4 and "Alpha" and "Bravo" for DEFCON 3. In addition, it had an "Emergency" level above DEFCON 1 that greatly resembled the EMERGCON scale described above.
افهم كيف يتم تحديد مستويات ديفكون. انتبه لمقاييس التأهب الأمريكية الأخرى. ابحث في تاريخ مقياس ديفكون.