In recent years, China’s People’s Liberation Army has undergone a massive modernization effort that has sought to not only expand their military presence around the world, but also to serve as the military backbone behind a broader diplomatic initiative. China wants to dethrone the United States as the most prominent super power on the globe, and in many respects, it’s well on its way. The Belt and Road initiative, for instance, will ensure China’s role as a central trading hub for the planet, while the loans it continues to offer to developing nations in the pursuit of that initiative continues to grant them leverage over national governments. China’s first military installation beyond its own borders was established in Djibouti, Africa last year, with others likely in the coming  years.

China’s Navy has expanded alongside its ambition, and thanks to a booming economy and massive labor force, an argument could easily be made that China represents the most pressing threat to American diplomatic and military dominance that the nation has faced since the end of the Cold War. But China’s rapid military expansion remains largely symbolic as a global competitor, and despite boasting the largest active duty military force on the globe, their troops currently pose little threat to the United States or its allies. While they continue to work to develop a truly blue-water Navy, there remains some significant limitations to their ability to field a ground presence in a conflict elsewhere in the world.

They lack a means of transporting their troops.

China’s active duty military stands at more than 2.6 million troops, with another half million reservists and and 619,000 more citizens fit for duty if the nation were to enact a military draft. Those numbers are not inconsequential regardless of the military technology at the disposable of any potential opponents, particularly because of China’s often successful efforts to steal and incorporate foreign technology into their own defensive enterprise. However, that massive troop count (the U.S. has only 1.3 million active duty personnel, as a comparison) comes with challenges all its own. Namely: a way to transport them.

Even today, when China conducts military training rotations, they have to establish their timetables based on the nation’s railway schedules. All those troops, their equipment and supplies all must travel by rail to get around within China’s own borders, meaning if they hope to engage in a war beyond Chinese soil, they’d better hope there’s a train to catch heading that way. No modern military has had to rely on rail transportation for troop mobilizations since World War I. That is, except for China. Even with the fastest growing Navy in the world and an added emphasis on military aviation, there remains little effort to develop large scale troop transport solutions, meaning any war China gets involved with will have to be local if they hope to deliver any sizable force.

They lack the training and experience of other national militaries.

The United States has been embroiled in nearly 20 years of counter insurgency and anti-terrorism warfare, which does not involve the same sort of strategy and tactics the nation would have to employ in a near-peer level conflict. However, all those years of fighting in different theaters have resulted in American troops being among the most experienced war fighters in the modern world — an advantage that would certainly be brought to bare in a conflict with any nation’s military.

China, on the other hand, has remained absent from the war on terror, and unlike Russia, it also hasn’t befriended any developing nations with wars to fight. That means despite having the largest military in the world, their service members lack any legitimate combat experience to draw from if war ever were to break out.

“I am retiring soon. My one big regret is that I never had a chance to fight in a war,” the China’s People’s Liberation Army’s top commander, General He Lei, said before retiring earlier this year. Despite a reputation for being hawkish, he wasn’t suggesting that he regretted that personally — what he meant was that he regretted not getting his military into the fight somewhere in the world, where they could hone their skills, strategy and technology in a way that would ensure they were effective and functional in a large scale conflict.

China is indeed on its way to becoming a global player with massive influence, but it will still be some time before their military poses a legitimate threat beyond Asia.