Duckwing,
I don't have access to the ICAO regs, but I think you have missed something.
As support, here's three very detailed links.
United Nations Convention on the Law of the Sea
Establishes that "territorial" waters and airspace (basically where the nation can do what it likes) is restricted to a 12 mile limit.
http://www.greenpeace.org/~intlaw/laws82-1.html#article_2_legal_status_of_the_terri San Remo Manual on International Law Applicable to Armed Conflicts at Sea
Points out that Peacetime rules in some instances apply even during wartime (territorial waters, for instance) and legitimacy of some activities (reconnaissance) in both peacetime and wartime.
http://www.icrc.org/icrceng.nsf/8ec4e051a8621595c12564670032d7ef/99cc2a9ab44033a5412562d70053b8a6?OpenDocument#6 Although I don't have access to the ICAO, I do have access to the US Airman's Information Manual. They are essentially the same in regulation IIRC.
This talks aboutintercepting OUTSIDE territorial waters, that is, in an ADIZ.
http://www.faa.gov/ATPubs/AIM/Chap5/aim0506.html b. Intercept phases (See FIG 5-6-1).
1. Phase One- Approach Phase.
During peacetime, intercepted aircraft will be approached from the stern. Generally two interceptor aircraft will be employed to accomplish the identification. The flight leader and wingman will coordinate their individual positions in conjunction with the ground controlling agency. Their relationship will resemble a line abreast formation. At night or in IMC, a comfortable radar trail tactic will be used.
Safe vertical separation between interceptor aircraft and unknown aircraft will be maintained at all times.
NOTE: These are instructions to the INTERCEPTOR 2. Phase Two- Identification Phase.
The intercepted aircraft should expect to visually acquire the lead interceptor and possibly the wingman during this phase in visual meteorological conditions (VMC). The wingman will assume a surveillance position while the flight leader approaches the unknown aircraft. Intercepted aircraft personnel may observe the use of different drag devices to allow for speed and position stabilization during this phase.
The flight leader will then initiate a gentle closure toward the intercepted aircraft, stopping at a distance no closer than absolutely necessary to obtain the information needed. The interceptor aircraft will use every possible precaution to avoid startling intercepted aircrew or passengers. Additionally, the interceptor aircrews will constantly keep in mind that maneuvers considered normal to a fighter aircraft may be considered hazardous to passengers and crews of nonfighter aircraft. When interceptor aircrews know or believe that an unsafe condition exists, the identification phase will be terminated. As previously stated, during darkness or IMC identification of unknown aircraft will be by type only.
Positive vertical separation will be maintained by interceptor aircraft throughout this phase. 3. Phase Three- Post Intercept Phase.
Upon identification phase completion, the flight leader will turn away from the intercepted aircraft. The wingman will remain well clear and accomplish a rejoin with the leader. 
