There is no shortage of reasons to worry about the outlook for the global economy and markets. On September 9, Brent crude, the international oil benchmark, surpassed US$100 a barrel in response to the intensification of hostilities in the Middle East.Bank of America warned that a renewed escalation in the conflict between Iran and the United States would prove more damaging to a global economy which “would no longer have the oil inventories buffer as it had early in the year”.Another threat is the recent surge in yields on long-term government bonds. The average yield on long-dated debt across the Group of 7 advanced economies has risen to its highest level since 2000, according to Bloomberg data. In the US, the yield on 10-year Treasury bonds is approaching the 5 per cent level beyond which higher yields start to hurt stocks.These two threats add to the persistent uncertainty caused by US President Donald Trump’s reckless trade tariffs, which are designed to hurt America’s friends more than its foes. The onslaught of protectionism has damaged US alliances around the world and contributed to the erosion of confidence in US assets.Trump, Ontario premier trade insults amid tariff warYet despite all these risks, the global economy and markets have held up remarkably well. In fact, the most compelling narrative since the beginning of last year is not the succession of shocks but the unexpected resilience of growth and the strong performance of equity markets.In a report on September 3, George Saravelos of Deutsche Bank noted that global economic data has beaten expectations for the longest period on record, excluding the 2009-10 liquidity-fuelled rebound from the 2008 global financial crisis.