MURGHAB, Tajikistan — On the outskirts of this wind-scoured town, founded in 1893 as a Russian military post, the construction of a new customs compound heralds the return of another major power.

When it opens this year, the sprawling new lot will accommodate much larger caravans of Chinese trucks than the existing trade depot, speeding the flow of clothing, electronics and household appliances that have lately flooded Central Asia, from nomadic yurts on the Kyrgyz steppes to ancient alleyways in Samarkand and Bukhara.

“Trade is growing between China and all these countries around it,” said Tu’er Hong, whose truck was one of about 50 from China transferring goods to Tajik drivers one day recently at the current post.

While China is seizing the spotlight in East and Southeast Asia with its widening economic footprint and muscular diplomacy, it is also quietly making its presence felt on its western flank, once primarily Russia’s domain.