The first World War OTL was, in geopolitical terms at least, partly a consequence of China's military and technological weakness. If China hadn't "pulled a Meiji" but had merely moderately reformed to the degree of say Ottoman Turkey and been only roughly 75% as militarily effective as Ottoman Turkey, I doubt very much if war would have broken out in 1914. OTL, China was no significant threat in the rear to the Russian Empire. A moderately modernised and militarily effective China allied to Germany could have placed the Franco-Russian alliance in check. Russia would probably have been less aggressive in supporting Serbia and France would have had to calculate the risk of potentially losing Indochina and would have been less keen to go along with Russia. And Britain would have been concerned about losing Hong Kong and Weihawei. Germany would probably also have abandoned the Schlieffen Plan. OTL, they wanted to knock France out quickly and then concentrate on Russia. TTL, they would be well aware that their Chinese ally was weaker than Russia and, to keep Russia overstretched with a three front war ( Eastern Front, Far Eastern Front and Caucasian Front) without them first knocking the Chinese out, they would have to significantly engage the Russians before taking any action against France.
And, if war did break out in 1914, the Western allies would have had a labour crisis by 1917 without the Chinese Labour Corps of OTL.