The series of economic and financial developments on Friday was a strange, confusing, exhausting microcosm of why the global economy risks a meltdown.
It showed the strange interplay at work between the Chinese government's actions in the escalating trade war with the United States, the sobering central banks that have limited power to deploy and an American president whose public statements often appear driven by complaint more than strategy .
President Trump arrives in France on Saturday for a meeting with the group of 7 industrialized nations, after setting the stage for fireworks and confusion. On a dizzying day, he seemed to be looking for who or what to blame for financial problems, first using Twitter to call his own Federal Reserve chief an enemy of the United States and then to urge US companies to quit to do business with China.
The global economy may still prove to be good; most economic data in the US has been solid. But if a recession and international trade collapse occurs in the coming year, the story of the episode could well use a chapter on the Friday collision of official actions in the Beijing government offices, the Grand Tetons in Wyoming and the Oval Office.
It became clear in real time how the risk of an escalating trade war and violation of long-standing economic and political ties could quickly exceed the ability of central banks – the normal first responders to financial distress – to do so.
President Trump's first initial approach adds to the risk in a delicate moment with major economies in Asia and Europe already overturned and the decision makers' capacity to contain the damage in question.  "Escalation, unpredictability, unpredictable nature of political developments are central to what is going on, and these are not things you can plug into an economic model," said Julia Coronado, president of MacroPolicy Perspectives, a financial consulting firm. “Something's broken. It is very dangerous. ”
A simple news cycle brings to life how these different policy areas can influence each other in unpredictable ways.
When Friday went up in the United States, China announced that they would impose US $ 75 billion in US goods tariffs, effective as of September 1. New US tariffs on Chinese goods come into effect on the same day.
Although there was no good news for those hoping for a trade peace between the world's two largest economies, proportional – more tit-for-tat response than escalation. The financial markets shrugged.
At 10 a.m. Eastern, Federal Reserve leader Jerome Powell gave a speech in Jackson, Wyo., Where the world's leading central bankers gather each August for an economic symposium. The financial world had been in suspense for any sign of what the Fed would do next.
The financial markets are increasingly pointing to a weak US economy. But with most measures, growth continues, and the labor market is fairly healthy. Will the Fed preferably act in response to market fluctuations and any evidence that business confidence is slipping?
Mr. Powell gave a nuanced speech signaling that the Fed was committed to a "risk management" approach, to adjust policy to try to prevent bad things from happening. His words kept the Fed's options open.
But he made it clear that a breakdown of global trade conditions was not the kind of thing that the Fed's interest rate policy was well suited to address.
"While monetary policy is a powerful tool," Powell said, "it cannot provide a definitive rulebook for international trade." The central bank can only adjust the policy to try to respond to how trade policy changes affect the overall outlook.
The implicit message: If uneven trade policies undermine the economy, the Fed's tools are likely to have only limited ability to overcome the damage. Interest rate cuts in that situation would be like giving painkillers to someone with a broken leg – better to have but not be able to solve the underlying problem.
Speech obviously didn't vote well in the White House. "
He followed that with those who urged American companies to disinvest from China. The stock market, which had been stable after the Powell speech, plunged.
Kl. At 5 pm, after financial markets closed, the president tweeted that he was escalating the trade war further, using a 15 percent duty to $ 300 billion Chinese value import from October 1, raising the $ 250 billion price to 30 percent from 25 percent.
The disconnect between sober, cautious central bankers and erratic policy that puts the economy at risk is not unique to the United States. Also speaking at the Jackson Hole symposium, Bank of England Governor Mark Carney spoke about a limited ability to use monetary policy to offset the damage from Britain's potentially messy exit from the EU this fall.
"Finally, monetary policy can only help smooth the adjustment to the big real shock that a sudden non-deal Brexit would entail," Carney said, and this ability will be limited by the need to keep inflation under control.  Beyond the trade war and Brexit, Powell's speech cited a potential Chinese crackdown on Hong Kong protesters and government instability in Italy as factors in a turbulent summer for the financial markets.
This is the global economy of 2019. A volatile political environment in many of the world's major economies continue to pose new risks, both for the financial markets and for businesses and consumers who make financial decisions every day.
But this is not like the 2007 and 2008 crisis, when central banks came together to meet a potential collapse of the global financial system, this episode, scary and catastrophic as it was, fit well with the tools of central banks.
This the situation is not. It can be comforting to think that there is a bunch of wise men and women operating behind the scenes and keeping the world economy from going into a ditch.
The lesson in recent months is that forces unfold that they cannot do much to contain. And if Friday is a guide, their caution and sobriety may even make things worse.