Diplomatic challenges are also mounting for China, as its military modernisation confronts the traditional US strategic dominance in East Asia
In his first two terms as commander of the world's largest military, Chinese President Xi Jinping has unleashed sweeping changes to its structure, posture and potency.
Over those 10 years, China has rapidly expanded and advanced its naval and rocket forces, purged thousands of officers over corruption, reformed its command operations and built bases deep in the maritime heart of Southeast Asia, reports Reuters.
Now come the tricky next steps for his Central Military Commission: implementing sweeping changes to its leadership, which commands China's two million-strong People's Liberation Army, potentially tightening Xi's grip over the military and its modernisation.
On Sunday, China's Communist Party kicked off its once-in-five-years congress, where it is expected to name replacements for four retirees among the six senior officers who serve under Xi on the commission. Among those expected to step down are the body's vice chairmen, Generals Xu Qiliang and Zhang Youxia, both 72. Zhang is widely viewed as a close Xi ally.
Their replacements must integrate increasingly complex forces that would be vital for a Taiwan invasion, say eight Asian and Western military attaches and seven security analysts, fulfilling Xi's long-held demand that the military can "fight and win wars".
Diplomatic challenges are also mounting, as China's military modernisation confronts the traditional US strategic dominance in East Asia.
The military envoys and three of the analysts say the commission will need to secure foreign base and port access for its expanding naval fleet as well as tackle possible external pressure to deepen international engagement over its arsenal of nuclear weapons. A slowing economy could also complicate modernisation.
Amid all those challenges, most of the incoming generals are likely to lack one element that marked at least some of their commission predecessors: combat experience.
Zhang and commission member General Li Zuocheng, who is also expected to retire, are some of the last two serving officers to have fought in the bloody border conflict with Vietnam that started with a troubled Chinese invasion in 1979 but rumbled on until the late 1980s.
Potential replacements include recent commanders from the reformed Eastern and Western theatre commands, responsible for Taiwan and the Indian border respectively, eight envoys say. Promotions also could come from the Southern Theatre command, home to vital naval bases.
Who is chosen could shed light on Xi's military priorities. Any operational choices are almost certainly to be balanced by political commissar promotions, given their on-going role to ensure the military serves the Communist Party rather than the country.
Operating out of an imposing and well-protected command building in western Beijing, the commission sits nominally under the party's Central Committee but in practice works closely under the Politburo's Standing Committee. Xi heads both bodies.
That overlap means has led some analysts caution against predictions of a Taiwan invasion based on any new commission lineup. The Standing Committee, not ambitious generals, would make such a momentous decision, they say.
"There is no shortage of senior military officers who internally parrot Xi's 'fight and win' mantra, but the conundrum for the PLA is the lack of operational experience," said Alexander Neill, a private military analyst.
James Char, a security scholar at Singapore's S Rajaratnam School of International Studies, said the PLA suffered from "shortcomings" in combined arms and joint operations.
"Its capacity for sustained power projection also remains limited at present," Char said.
China's Defence Ministry did not respond to requests for comment.