With each passing day, it becomes increasingly evident that US president Donald Trump\u2019s administration cares less about economics and more about the aggressive exercise of political power. This is obviously a source of enormous frustration for those of us who practice the art and science of economics. But, by now, the verdict is self-evident: Trump and his team continue to flaunt virtually every principle of conventional economics. Trade policy is an obvious and essential case in point. Showing no appreciation of the time-honoured linkage between trade deficits and macroeconomic saving-investment imbalances, the president continues to fixate on bilateral solutions to a multilateral problem\u2014in effect, blaming China for America\u2019s merchandise trade deficits with 102 countries. Similarly, his refusal to sign the recent G7 communiqu\u00e9 was couched in the claim that the US is like a \u201cpiggy bank that everybody is robbing\u201d through unfair trading practices. But, piggy banks are for saving, and in the first quarter of this year, America\u2019s net domestic saving rate was just 1.5% of national income. Not much to rob there! The same can be said of fiscal policy. Trump\u2019s deficit-busting tax cuts and increases in government spending make no sense for an economy nearing a business-cycle peak and with an unemployment rate of 3.8%. Moreover, the feedback loop through the saving channel only exacerbates the very trade problems that Trump claims to be solving. With the Congressional Budget Office projecting that federal budget deficits will average 4.2% of GDP from now till 2023, domestic saving will come under further pressure, fuelling increased demand for surplus saving from abroad and even bigger trade deficits in order to fill the void. Yet, Trump now ups the ante on tariffs\u2014in effect, biting the very hand that feeds the US economy. So, what Trump is doing is not about economics\u2014or at least not about economics as most academics, political leaders, and citizens know it. Sure, Trump has been quick to draw on some fringe mutations of economics\u2014say, Arthur Laffer\u2019s infamous back-of-a-napkin supply-side musings\u2014but, none that have withstood the test of time and rigorous empirical validation. But, why single out economics? The same complaint could be made about Trump\u2019s views on climate change, immigration, foreign policy, or even gun control. It\u2019s power-politics over fact-based policymaking. This should not be all that surprising. Trump\u2019s battle with China merely underscores his eagerness\u2014transparent from the start\u2014to use economics as a foil in his pitch to \u201cmake America great again.\u201d Contrary to his bluster over unfair trade deficits, China\u2019s real challenge to the United States is less about economics and more about the race for technological and military supremacy. Indeed, the pendulum of geopolitical leadership is now in motion. China\u2019s massive pan-Asian infrastructure plan, the Belt and Road Initiative, together with its muscular behaviour in the South China Sea, pose far greater threats to American hegemony than does one bilateral piece of a much larger multilateral trade deficit. At the same time, China\u2019s recent efforts to build the institutions of an alternative financial architecture\u2014spearheaded by the Asian Infrastructure Investment Bank and the New (BRICS) Development Bank\u2014stand in sharp contrast to an increasingly inward-looking US. Much has been written about the historical trajectory of great powers and the military conflicts that often arise during their rise and fall. This is where economics eventually comes back into play. Geostrategic power and economic power are joined at the hip. As Yale historian Paul Kennedy has long stressed, a condition of \u201cimperial overreach\u201d arises when the projection of military power outstrips a country\u2019s shaky economic foundations. It has been 30 years since Kennedy warned that the US, with its excessive defence spending, was increasingly vulnerable to such overreach. But, then, the would-be heirs to the US faded: the Soviet Union collapsed, Japan\u2019s economic miracle imploded, and Germany became entangled in reunification and European integration. An unthreatened America plodded on. China, of course, was barely on the radar screen back then. Moreover, in 1988, the US had a net domestic saving rate of 5.6% of national income\u2014only slightly below the 6.3% average of the final three decades of the twentieth century, but, nearly four times the current rate. Back then, the US was spending $270 billion on defence\u2014less than half the $700 billion authorised in the current budget, which now outstrips the combined military outlays of China, Russia, the United Kingdom, India, France, Japan, Saudi Arabia, and Germany. Meanwhile China has ascended. Back in 1988, its per capita GDP was just 4% of the US level (in purchasing-power-parity terms). This year, that ratio is close to 30%\u2014nearly an eightfold increase in just three decades. Can power politics offset the increasingly tenuous fundamentals of a saving-short US economy that continues to account for a disproportionate share of global military spending? Can power politics contain the rise of China and neutralise its commitment to pan-regional integration and globalisation? The Trump administration seems to believe that America has reached a propitious moment in the economic cycle to play the power game. Yet, its strategy will succeed only if China capitulates on the core principles of the growth strategy that frames president Xi Jinping\u2019s great power aspirations: indigenous innovation, technological and military supremacy, and pan-regional leadership. Like Trump, Xi does not do capitulation. Unlike Trump, Xi understands the linkage between economic and geostrategic power. Trump claims that trade wars are easy to win. Not only is he at risk of underestimating his adversary, but, he may be even more at risk of over-estimating America\u2019s strength. The trade war may well be an early skirmish in a much tougher battle, during which economics will ultimately trump Trump. The author is a faculty member at Yale University and former chairman of Morgan Stanley Asia.