President Donald Trump is breaking with recent U.S. convention by portraying China as a rival that wants to undermine American prosperity. But it may take more than an aggressive tone to change the complex relationship between two economies that are joined at the hip.

In a new national-security strategy released Monday, the White House lumped China with Russia as powers seeking to "challenge American power, influence, and interests," and attempting to erode the country's security and prosperity. "We will attempt to build a great partnership with those and other countries, but in a manner that always protects our national interest," Trump said in a speech in Washington.

The new rhetoric contrasts with the more collaborative approach of former President Barack Obama, who courted China as an economic partner even as the U.S. asserted its military power in Asia.