President Donald Trump made another move that surprised many folks in both Washington and Beijing — he announced that his threat to raise $50 billion in tariffs against China is back on the table. Trump posted a detailed list of national security concerns and grievances against China on the White House website. And Trump’s message to China was succinct and clear: “From now on, we expect trading relationships to be fair and to be reciprocal.”

What made this latest move by Trump surprising to some was the fact that U.S. Commerce Secretary Wilbur Ross had just arrived in Beijing over the weekend to work on outlining a new trade deal after an apparent truce was called by Trump in the looming trade war two weeks ago. Chinese Commerce Minister Mei Xinyu expressed his displeasure at the sudden change, stating, “Since the U.S. side can talk about imposing tariffs again, we can also put forward our previously published retaliation lists.” But Mei also added that he believed Trump was merely engaging more of his “unpredictability strategy,” adding, “every flip-flop and U-turn is simply depleting and squandering [U.S.] credibility.”

Once again, it appears that Trump is engaged in more than merely seeking a level playing field for U.S.-China trade relations, although that is a significant piece of the puzzle. Recall how suddenly North Korea changed its rhetoric and stance on seeking peace and denuclearization almost immediately after Kim Jong-un’s second visit to Beijing. Trump’s willingness to walk away from the much-ballyhooed Singapore summit proved that he would not be manipulated into a bad deal. It also served to call China’s bluff. And now he’s ratcheting up the pressure again. When it comes to negotiations, Trump doesn’t like to lose.