( CNN ) -- Since President Xi Jinping assumed power , he 's reshaped China 's foreign policy by recalibrating its stresses on sovereignty and stability , what the Chinese call wei quan and wei wen . On the one hand , China has stepped up its emphasis on sovereignty , especially concerning its territorial dispute with Japan over the Diaoyu Islands ( or the Senkakus , as they 're known in Japan ) . Beijing has streamlined its various maritime agencies to make them more efficient and better coordinated , and it keeps sending government vessels to the area to demonstrate its jurisdiction over this region . More recently , it announced a new Air Defense Identification Zone ( ADIZ ) in the East China Sea to assure its sovereign security over territory , territorial water and space in the ADIZ . On the other hand , China has attached more importance to its peripheral stability . Despite its earlier skirmish over Ladakh with India in May , it cut a border defense co-operation agreement with New Delhi , to avoid mutual tailing between their patrols in border areas where there is no common understanding of the line of actual control . And recently , President Xi and Premier Li Keqiang visited five out of 10 ASEAN countries , and wrapped up a cooperative deal with Vietnam to jointly develop an oil well in the mouth of the Gulf of Tonkin . China has also furthered its relations with major powers -- Xi visited Russia and the U.S. within the first three months of coming to power , promoting a `` new type of major country relationship . '' However , the quest for sovereignty and stability at the same time could prove challenging . China 's ADIZ announcement is turning into such a case . Origins of the ADIZ . The concept and practice of ADIZ are not China 's invention . Rather , it was invented by the U.S. in 1951 , with a purpose of identifying , through various means , incoming aircraft toward North America . An ADIZ would usually be much bigger than one 's territorial space , to allow sufficient time for such identification . Last weekend , the Chinese government announced its East China Sea ADIZ , asking foreign military planes flying over this area to identify themselves or , if necessary , the government would take defensive military action to enforce their identification . It is noted that the ADIZ is a national mandate , rather than demanded by any international law . Therefore , any other country has to make its own sovereign choice to follow or not . The establishment of the East China Sea ADIZ looks to be China 's latest attempt to stress sovereignty and stability . The purpose of such identification is to assure China 's sovereignty over its airspace without disrupting the international law of freedom of flight through international airspace . Obviously , China is able to identify those foreign civilian airlines which routinely fly to and from China . China will also be able to monitor and identify some foreign military aircraft flying over this zone . Establishing such a zone would allow China , ideally , additional time to predict if some of the flights over the area would be harmful and , consequently , if its defense establishment should take precautionary measures . Challenge to status quo ? As establishing an ADIZ is a national endeavor rather than one mandated by international law , it is predictable other stakeholders could view it a challenge to the status quo , which suits their national interests . Soon after China 's ADIZ was announced , the U.S. sent two B-52 bombers into the new air zone on what the U.S. says was a pre-planned trip . It is understood that the U.S. strategic bombers neither loaded bombs nor were escorted by jet fighters , and did n't go too close to China 's territorial space , signaling that the mission was not intended as a military threat . Such a restrained challenge seems to have led China to properly balance its quest for sovereignty and stability . If and when China 's newly declared ADIZ is truly challenged , as long as China could identify the incoming foreign aircraft and manage the challenge to a certain degree , China would not send aircraft to `` greet '' them . But certainly , if the incoming foreign aircraft did not respond to China 's query of identity , and if China detected a threatening posture , its air force would act in a defensive way . Though the U.S. has presented its challenge to China establishing such a zone , the country 's ADIZ may have more to do with Japan . Japan 's own ADIZ has been as close as to 130 kilometers from China , and includes the Diaoyu , or Senkaku , Islands . If China 's inclusion of Diaoyu Islands is intolerable to Japan due to their dispute over this area , Japan 's inclusion of the same islands , some four decades ago , has much earlier provoked a similar degree of irritation . Japan 's establishment of its ADIZ was a breach of the status quo at that time . Japan further pushed the envelope last year by `` nationalizing '' the main islands , representing another effort to break the existing status quo . Its persistent changing of the status quo can not go unchallenged . China 's efforts to strike a balance between sovereignty and stability are destined to be difficult . However , facing increasing security challenges , Beijing is likely to respond in kind , while abiding by international law . The opinions in this article are solely those of Shen Dingli , a professor and associate dean of the Institute of International Studies at Fudan University in Shanghai .
President Xi has reshaped China 's foreign policy , stressing sovereignty and stability . Shen Dingli : East China Sea ADIZ looks to be China 's latest attempt to stress this approach . Facing increasing security challenges , Beijing is likely to respond in kind , Shen Dingli says .