China announced military exercises around Taiwan on Monday, mobilizing naval, air, ground and missile forces for what the People’s Liberation Army described as a “stern warning” to opponents of Beijing’s claims to the island. As part of the drills, Chinese authorities said that seven zones of ocean and air space around Taiwan would be sealed off for live-fire exercises to be held on Tuesday.

中国周一宣布在台湾周边举行军事演习，此次演习调动了海军、空军、陆军和导弹部队，中国人民解放军称此举是对反对北京对该岛主权主张者的“严重警告”。作为演习的一部分，中国当局表示将封锁台湾周边七个海域和空域，以便周二进行实弹演习。

The operation, called “Justice Mission 2025,” marked the first major military exercises around Taiwan since April by the People’s Liberation Army, or P.L.A. They appeared designed to display Beijing’s growing capabilities to encircle Taiwan. They also came after the administration of President Trump revealed a proposed package of arms sales to Taiwan earlier this month that would be worth more than $11 billion and include powerful high-mobility artillery rocket systems known as HIMARS.

这次行动名为“正义使命—2025”，是自4月以来中国人民解放军在台湾周边举行的首次大规模军事演习。此次演习似乎旨在展示北京日益强大的包围台湾的能力。此前，特朗普政府本月早些时候披露了一项拟议的对台军售方案，价值超过110亿美元，其中包括被称为HIMARS的高机动性多管火箭炮系统。

Senior Colonel Shi Yi, a spokesman for the Eastern Theater Command, the part of the Chinese military that is conducting the exercises, said it would simulate blockading ports and establishing Chinese dominance to the east of Taiwan — the direction from which any potential wartime support from the United States and its allies would likely come. Taiwan’s Ministry of National Defense said that it had deployed forces as a precaution in the heightened tensions.

负责此次演习的中国军队东部战区发言人施毅大校表示，演习将模拟封锁港口，确立在台湾东部的控制——美国及其盟友在战时可能从这个方向提供支援。台湾国防部表示，鉴于局势紧张，已部署兵力以防万一。

“These exclusion zones do seem to be a very realistic representation of where the P.L.A. would operate from to enforce a blockade of Taiwan,” said David Sacks, a fellow at the Council on Foreign Relations who studies relations between the United States, China and Taiwan.

“这些禁区似乎非常真实地反映了解放军将从哪些区域行动来实施对台湾的封锁，”美国外交关系委员会研究美中台关系的学者戴维·萨克斯说。

Colonel Shi said the exercises were “a legitimate and necessary action to safeguard China’s sovereignty and national unity.” But Beijing gave no specific reason for holding the exercises now, and experts said several factors may have prompted China’s leader, Xi Jinping, to renew threats of an armed attack on Taiwan.

施毅大校表示，此次演习是“捍卫国家主权、维护国家统一的正当必要行动”。但北京没有给出此时举行演习的具体原因，专家表示，几个因素可能促使中国领导人习近平再次发出对台湾进行武装攻击的威胁。

“The timing of P.L.A. drills are increasingly disconnected from single political events,” said Amanda Hsiao, the director of China coverage at the Eurasia Group, a company that advises clients on global risks. “This drill may be as much intended for domestic audiences as much as Taiwan and U.S. ones.”

“人民解放军演习的时机与单一政治事件的关联越来越弱，”为客户提供全球风险咨询的欧亚集团的中国事务主管萧嫣然说。“这次演习的目的可能既是针对台湾和美国，也是针对国内受众。”

China’s main state-run television broadcaster, CCTV, said the exercises, which began on Monday, included destroyers, fighter bombers and drones conducting “maritime and airborne search-and-destroy operations, simulated strikes on land and live-fire naval drills.” It also said Chinese forces were training to win air superiority and hunt submarines to the island’s east.

中国官方电视台中央电视台报道称，此次演习于周一开始，包括驱逐舰、战斗轰炸机和无人机参与“对海突击、区域制空、搜索反潜等演练，检验了海空协同、精准寻歼能力”。报道还称，中国军队正在训练以夺取制空权，并在该岛东部海域搜寻潜艇。

Taiwan’s coast guard reported spotting four Chinese coast guard ships to the north and east of the island. China has often used its coast guard to assert territorial claims.

台湾海岸警卫队报告称，在台湾岛北部和东部海域发现了四艘中国海警船。中国经常利用其海岸警卫队来声张领土主张。

China’s Communist Party leaders have long maintained that Taiwan, an island-democracy of 23 million people, is Beijing’s territory. Mr. Xi has been building up his nation’s military to apply pressure on Taiwan, and perhaps one day try to take it by force.

中国共产党领导层长期坚持认为，有2300万人口、实行民主制度的台湾是北京的领土。习近平近年一直在加强中国军力建设，以向台湾施压，并可能在未来某一天试图以武力夺取台湾。

But the People’s Liberation Army leadership has also been in turmoil. Dozens of commanders and generals have been removed in recent years, some formally dismissed and investigated for corruption and other suspected misconduct, others disappearing from public view without explanation.

但与此同时，解放军高层也陷入动荡。近年来，数十名指挥官和将领被免职，其中一些人被正式解职并因涉嫌腐败和其他不当行为接受调查，有的则在没有任何解释的情况下从公众视野中消失。

The upheavals have magnified doubts among experts about the Chinese military’s readiness to seize Taiwan by force. Last week, Mr. Xi appointed a new commander — Yang Zhibin, a former air force pilot — to lead the Eastern Theater Command, which is in charge of the area around Taiwan.

这些人事动荡加剧了专家对中国军队是否具备以武力夺取台湾能力的疑虑。上周，习近平任命曾任空军飞行员的杨志斌出任东部战区司令员，该战区负责台湾周边地区。

本月早些时候，中国领导人习近平在北京与新晋升的将军们合影。照片左后方的那位男子被确认为杨志斌，他被任命为东部战区司令员，该战区涵盖台湾。

While General Yang appears to have been acting commander of the Eastern Theater for months, the exercises were announced right after he was officially put in charge, said Lin Ying-yu, an associate professor at Tamkang University in Taiwan who studies the Chinese military.

研究中国军方的台湾淡江大学副教授林颖佑表示，杨志斌已担任东部战区代司令数月，此次演习正是在他正式就任后立即宣布的。

“I personally think this could also be considered a new test for him,” Professor Lin said.

“我个人认为，这也可以被视为对他的一次新的测试，”林颖佑说。

Mr. Trump and Mr. Xi have been trying to stabilize relations ahead of a planned summit in Beijing in April. Although China’s initial reaction to the arms sales to Taiwan was relatively muted, the exercises may be intended to convey China’s anger, said Mr. Sacks from the Council on Foreign Relations.

特朗普和习近平一直在努力稳定两国关系，为4月在北京举行的峰会做准备。外交关系协会的萨克斯表示，尽管中国最初对向台湾出售武器的反应相对克制，但此次演习可能意在表达中方的不满。

“This response is expected, given the scale of the arms sale package,” Mr. Sacks said. Mr. Xi appeared “confident he can push without provoking a counter response from President Trump.”

“鉴于这次军售方案的规模，这样的反应是可以预期的，”萨克斯说。他认为，习近平似乎“有信心在不引发特朗普总统反制的情况下施加压力”。

On Monday, a Chinese-language social media account run by China’s Ministry of Foreign Affairs said the proposed weapons sales would “seriously damage peace in the Taiwan Strait.”

周一，中国外交部运营的一个中文社交媒体账号称，拟议中的武器销售将“严重破坏台海和平”。

Mr. Xi may also intend the exercises as a warning to Japan against supporting Taiwan in a possible conflict. Beijing bitterly condemned Japan’s new prime minister, Sanae Takaichi, after she said in November that an attempt by China to blockade or seize Taiwan could be seen as a “survival-threatening” situation in her country — words that could, under Japanese law, allow the deployment of military forces.

习近平此举或许也意在警告日本，不要在可能发生的冲突中支持台湾。北京此前曾严厉谴责日本新任首相高市早苗。她在11月表示，如果中国试图封锁或夺取台湾，可能会被视为对日本构成“生存威胁”的事态——按照日本法律，这种表述可能为自卫队的出动提供依据。

The timing of China’s exercises “has the flavor of an indirect attack aimed at Japan,” said Professor Lin, the Taiwanese military expert.

林颖佑认为，中国此次军演的时机“带有针对日本的间接攻击意味”。