The wonder of the United States is not waning. The New York stock exchanges continue to break records with some companies having valuations exceeding a trillion dollars, which has never been seen before. By way of comparison, the Paris-listed company with the largest capitalization, LVMH, (240 billion euros) barely exceeds a quarter of the value of the big stars of Wall Street. The new stars, supported by artificial intelligence and their suppliers, the semiconductor manufacturers, have dethroned the Internet giants. The exceptional success of business leaders like Elon Musk in electric vehicles and now in the space industry or Jeff Bezos has no equivalent in Europe.
Hence the widely shared conclusion: faced with the rise of China and the successes of American companies, Europe has begun a period of economic decline, which, in the context of geopolitical tensions, has resulted in a fall in its influence on the international scene. The growth figures are conclusive. Since the Covid crisis, the European Union has struggled to reach 1% on average while the United States has been above 2%. The figures for productivity growth speak even further. While it is stagnating on the Old Continent, across the Atlantic, it has grown, over the last four quarters, excluding agriculture, by 2.8%.
These results are all the more surprising as they do not seem to have been affected by Donald Trump's policy, while one could have at least expected more uncertainty on the part of business leaders about the instability generated by this policy. The multiplication of decisions in one direction and the next day in the opposite direction in terms of customs duties certainly contributed to the reorientation of certain supply chains, but did not cause severe falls in the sectors concerned.
The outbreak of war in the Middle East caused oil and natural gas prices to rise to the benefit of American groups that had the capacity to increase their production. This has generated new external revenues and substantial profits. But it has also caused a rebound in inflation that makes it almost impossible for the Federal Reserve to cut interest rates. However, the occupant of the White House had launched into a virulent criticism of his previous president who refused to meet this demand in the name of the institution's independence. The new president, chosen because he could have a more conciliatory attitude, will find himself in a very difficult situation in the face of this resurgence of inflation, especially if, on top of that, he will have to defend the dollar.
The success of the American economy is also financial. The country's weight in the global economy is such that doubts about the sustainability of this success would have repercussions far beyond its borders. The two major crises of the last century, that of 1929 and that of the sub-prime crisis in 2007, were born in the United States. There were of course other local crises, such as the euro crisis after 2010 or the Asian crisis in the 1990s, but they did not have significant consequences for other countries.
On the other hand, if a country's prosperity is based solely on the appreciation of the financial markets, and since this appreciation can be very volatile, a new major crisis in the United States cannot be ruled out. It could come from several factors. First, there is the fragility of the financial system. Prudential standards and reporting obligations are less stringent than in Europe. Thus a whole system of "private credit" has developed where funds that are financed on the market offer loans to companies, thus competing with the banks. Several warnings have been issued recalling the similarity of the risk with the mechanisms that triggered the sub-prime crisis.
The second element of concern concerns public deficits, which continue to increase in a context where interest rates are higher than in Europe, which increases the debt burden. The published figures show a public debt ratio to GDP of 120%. The IMF has forecast that this rate will rise to 143% by the end of 2029. As the debt ceiling is set by Congress, each year its increase gives rise to tense debates to get out of the "shut-down", a situation where the state can no longer spend.
But the most worrying element is that this debt, which amounts to 39,000 billion dollars, is not financed, unlike what we observe in the euro zone, by American savings, but very largely by foreign capital because of the heavy deficit in the trade balance and the current account balance. In 2025, it reached $1,200 billion. We constantly stigmatise the excesses of public debt in the euro zone and especially with regard to France. But France has a surplus in its current payments. The public debt of the euro zone amounts to 87% of GDP in 2025, much less than in the United States, where its definition is not as clear as in Europe given the federal nature of the institutions.
The answer, which is intended to be reassuring, revolves around the particular character of the dollar, which is said to be the world's reserve currency and which confers a kind of impunity on the country. This was true twenty years ago, but it is no longer the case with the creation of the euro and with the will of China, which is accumulating external surpluses and gradually reducing the share of dollar securities in its reserves. However, the world is experiencing more and more international tensions, at the center of which is often the American administration with the sometimes aggressive statements of its president. Is this the best way to maintain the support of its creditors? Certainly not.
The United States is experiencing unprecedented financial prosperity but with a very high concentration of wealth. 1% of households hold 35% of the national wealth compared to only 21% in 1980. This concentration is the result of the boom in the price of high-tech companies. But by definition, markets, especially for this asset class, are very volatile. A reversal of judgments on the financial outlook offered by artificial intelligence would inevitably provoke a correction that would be all the more violent as the past rise has been rapid and massive.
It would affect all confidence in the American economic and financial system. If the State had sufficient reserves to protect itself against a possible shock, the turbulence would be real but the means to deal with it would exist. But we are not in this configuration because of the country's heavy external debt and foreign policy which, with the exception of Japan, has been aggressive against its creditors. The American president's trip to China has produced only images and façade words. In the event of a crisis, the Chinese central bank is unlikely to come to the rescue of the dollar, a currency from which it is gradually but continuously offloading. Relations with Europe are just as tense, especially after the statements on Greenland and the accusations levelled at its leaders over insufficient military spending.
Stock market bubble and internal and external financial fragility. The reasons to be amazed are debatable, but the financial risks are indisputable.