Sides 'knew risk of close encounters'
Sunday's collision off Hainan Island was an 'accident looking for somewhere to happen', some analysts believe, with both Beijing and Washington voicing separate concerns over close surveillance encounters.
Officials and scholars in Washington said China had frequently objected to US spy flights in private meetings with American officials and made formal objections through the Association of Southeast Asian Nations (Asean) Regional Forum on security.
A general proposal to halt coastal surveillance lodged with the fledgling regional forum in 1998 as a so-called confidence-building measure between regional militaries was not approved.
'They have made quite clear for some time that they find this sort of operation an irritant to say the least,' one US official said. 'Of course, from our side we believe this concern goes hand-in-hand with protecting their military build-up, particularly across the Taiwan Strait.'
The US, meanwhile, has voiced its own concerns as China's responses to its continued use of flights like the EP-3E Aries II operation off Hainan became more aggressive in recent months.
A US EP3 had to make an emergency landing on Hainan Island on Sunday after a collision with a Chinese fighter plane. The Chinese pilot is still missing and China has detained the 24 crew of the US plane.
It is understood a similar collision nearly occurred in mid-December - also southeast of Hainan Island - when the US claimed a Chinese F-8 fighter came within six metres of an EP-3.
US State Department and Pentagon officials lodged a formal protest with their Chinese counterparts in both Beijing and Washington.
A mutual acknowledgement that both nations' militaries would come into ever closer contact sparked the creation of an agreement governing engagements in international waters and airspace.
After months of negotiation, former US defence secretary William Cohen and Chinese Defence Minister Chi Haotian signed the Military Maritime Consultative Agreement in early 1998.
The document - fuelled principally by a naval stand-off in 1994 - essentially paved the way for future talks but did not stipulate actual 'rules of the road'. Tensions rose after a Chinese submarine and fighter jets followed the aircraft carrier Kitty Hawk in October 1994.
The document was 'designed to establish a process of dialogue between the militaries that will enhance our understanding and trust has our militaries and air forces come in close proximity to each other,' one recent US Department of Defence study noted.
The agreement is much less detailed than the Incidents At Sea pact signed between the US and the former Soviet Union after an American spy ship was rammed in the Black Sea in 1998.
Regular talks on a more extensive agreement were carried out but put on ice following the US-led Nato bombing of the Chinese embassy in Belgrade nearly two years ago. Talks have since resumed but remain at a 'basic' level, one US official said.