共機自2月底迄今已多日未現蹤於台海周邊，引發諸多揣測。各方推論可能原因包括中共召開兩會維穩至上、川習會3月底召開在即鋪陳善意、立法院即將審議國防特別條例降低需求、以及美伊戰爭衝擊能源安全等。除了上列可能因素外須持續觀察外，另須關注者，為何僅有共機停止侵擾台灣周邊空域，但共艦仍然每日出沒於台灣四周海域，且固定維持6艘？
綜合論之，近年來習近平刻意擴張紀委系統在軍中影響力，除了將軍紀委自政工系統脫離獨立外，更將其提升至中央軍委層級，張升民且升任中央軍委副主席。軍紀委系統成為習近平整肅軍隊的主要工具。張又俠遭拘留一事對軍心士氣必有影響，除公布此事時採取的諸多措施外，近日習近平在接見全國人大軍警代表團時，仍強調「軍中絕不能有對黨懷有二心之人」，即可看出。
為何CIA發布影片兩周後，共機就停止在台海周邊活動？如果是中共對台釋出善意，為何共艦未減少？為何中共官媒報導一線部隊殲16戰機飛行員對黨國效忠？是否共軍內部確實出現對一連串高階將領遭政治整肅而心生不滿、對軍紀委系統在軍中權力過度膨脹欺壓其它系統而忿忿不平、對人事晉升職缺不公而失望挫折之情緒耳語，加上CIA刻意釋出的影片，軍紀委系統必然會警覺加強監視官兵。尤其對於海空一線兵力，防止叛逃必然是確保軍隊政治安全的重中之重。在無法確保絕對安全且中央正召開兩會之際，停止任何可能出差錯的行動，是確保絕對安全的方法。
共機叛逃可能性高於共艦，因為飛行員個人便可決定去留。停止共機活動的同時，卻維持固定數量共艦在台灣周邊海域駐留，其目的是否為防範共機叛逃台灣？眾所皆知，水面作戰艦除了從事海上作戰外，亦具備防空作戰能力。共艦環繞台灣周邊，等同建立一道防空網，可攔截任何空中目標，包括共機。我方於推論近日無共機擾台之原因時，亦應觀察共軍航空兵部隊內部近日是否明顯增加政治課程？釐清台海周邊無共機卻有共艦背後的真實原因。
PLA aircraft have not been observed around the Taiwan Strait for several days since late February, prompting considerable speculation. Various explanations have been proposed, including the Chinese Communist Party’s prioritization of stability during the convening of the “Two Sessions,” a potential gesture of goodwill ahead of a possible Trump–Xi meeting at the end of March, the Legislative Yuan’s upcoming review of a special national defense bill that may reduce pressure, and the potential impact of a U.S.–Iran conflict on energy security. Beyond continuing to observe these possible factors, another issue also warrants attention: why have PLA aircraft ceased intrusions into airspace around Taiwan, while PLA Navy vessels continue to appear daily in waters surrounding Taiwan, consistently maintaining a presence of six ships?
Taken together, in recent years Xi Jinping has deliberately expanded the influence of the discipline inspection system within the PLA. In addition to separating the CMC Discipline Inspection Commission from the political work system and making it an independent body, it has also been elevated to the Central Military Commission level, with Zhang Shengmin promoted to vice chairman of the CMC. The discipline inspection system has thus become Xi Jinping’s primary instrument for purging the military. The detention of Zhang Youxia inevitably has implications for troop morale. In addition to the various measures taken when the detention was announced, Xi Jinping recently emphasized during a meeting with the PLA and People’s Armed Police delegation to the National People’s Congress that “there must absolutely be no one in the military who harbors divided loyalty toward the Party,” which reflects the leadership’s concerns.
Why did PLA aircraft cease activities around the Taiwan Strait two weeks after the CIA released its recruitment video? If this were a gesture of goodwill by Beijing toward Taiwan, why have PLA Navy vessels not decreased in number? Why did Chinese state media highlight the loyalty of a frontline J-16 fighter pilot to the Party-state? It is possible that within the PLA there has indeed been dissatisfaction and private discussion stemming from a series of political purges of senior officers, resentment toward the expanding authority of the discipline inspection system within the military and its pressure on other institutional systems, and frustration over perceived unfairness in personnel promotions and vacancies. Combined with the CIA’s deliberately released recruitment video, the discipline inspection system would inevitably become more vigilant and intensify monitoring of officers and enlisted personnel. In particular, among frontline naval and air units, preventing defections would naturally become a top priority for safeguarding the political security of the military. Under circumstances where absolute security cannot be guaranteed and the central leadership is convening the Two Sessions, halting any operations that might risk mistakes would be a way to ensure absolute security.
The likelihood of defection is higher for PLA aircraft than for PLA Navy vessels, because a pilot alone can decide whether to leave. While PLA aircraft activities have ceased, the continued presence of a fixed number of PLA Navy vessels in waters surrounding Taiwan raises the question of whether their purpose is to guard against potential defections of PLA aircraft to Taiwan. It is well known that surface naval ships, in addition to conducting maritime combat operations, also possess air defense capabilities. The presence of PLA Navy vessels encircling Taiwan effectively creates an air defense network capable of intercepting any aerial target, including PLA aircraft. When considering the reasons behind the recent absence of PLA aircraft around Taiwan, observers should also examine whether political education sessions have noticeably increased within PLA aviation units in recent days. Clarifying this issue may help reveal the true reasons behind the absence of PLA aircraft—but the continued presence of PLA Navy vessels—around the Taiwan Strait.