The billions the Chicoms have invested in upgrading their military had to have come, in large part, from W-M dollars. Their economy does depend upon us, but the enormous trade imbalance in their favor cannot be helping our economy.
Actually, the trade imbalance does help our economy. We get the products of their labor, and they get worthless pieces of paper (dollars).
Only when they take those pieces of paper back to someone who wants them can they derive benefit from them. Eventually someone brings the paper back to the US and trades it for US goods and services.