The sense of alarm is enhanced by the fact that every inhabited part of the globe is now in trouble.

The United States, the world’s largest economy, is almost certainly in a recession. So is Europe. So probably are significant economies like Canada, Japan, South Korea, Singapore, Brazil, Argentina and Mexico. China, the world’s second-largest economy, is expected to grow by only 2 percent this year, according to TS Lombard, the research firm.

For years, a segment of the economic orthodoxy advanced the notion that globalization came with a built-in insurance policy against collective disaster. So long as some part of the world economy was growing, that supposedly moderated the impact of a downturn in any one country.

The global recession that followed the financial crisis of 2008 beggared that thesis. The current downturn presents an even more extreme event — a worldwide emergency that has left no safe haven.

When the pandemic emerged, initially in central China, it was viewed as a substantial threat to that economy. Even as China closed itself off, conventional wisdom held that, at worst, large international companies like Apple and General Motors would suffer lost sales to Chinese consumers, while manufacturers elsewhere would struggle to secure parts made in Chinese factories.

But then the pandemic spread to Italy and eventually across Europe, threatening factories on the continent. Then came government policies that essentially locked down modern life, business included, while the virus spread to the United States.

“Now, anywhere you look in the global economy we are seeing a hit to domestic demand on top of those supply chain impacts,” said Innes McFee, managing director of macro and investor services at Oxford Economics in London. “It’s incredibly worrying.” 

Oxford Economics estimates that the global economy will contract marginally this year, before improving by June. But this view is likely to be revised down sharply, Mr. McFee said.

Trillions of dollars in credit and loan guarantees dispensed by central banks and governments in the United States and Europe have perhaps cushioned the most developed economies. That may prevent large numbers of businesses from failing, say economists, while ensuring that workers who lose jobs will be able to stay current on their bills.

“I am attached to the notion that this is a temporary crisis,” said Marie Owens Thomsen, global chief economist at Indosuez Wealth Management in Geneva. “You hit the pause button, and then you hit the start button, and the machine starts running again.”

But that depends on the rescue packages proving effective — no sure thing. In the typical economic shock, government spends money to try to encourage people to go out and spend. In this crisis, the authorities are demanding that people stay inside to limit the virus.

“The longer this goes on, the more likely it is that there will be destruction of productive capacity,” Ms. Owens Thomsen said. “Then, the nature of the crisis morphs from temporary to something a bit more lasting.”

Worldwide, foreign direct investment is on track to decline by 40 percent this year, according to the United Nations Conference on Trade and Development. This threatens “lasting damage to global production networks and supply chains,” said the body’s director of investment and enterprise, James Zhan.

“It will likely take two to three years for most economies to return to their pre-pandemic levels of output,” IHS Markit said in a recent research note.

In developing countries, the consequences are already severe. Not only is capital fleeing, but a plunge in commodity prices — especially oil — is assailing many countries, among them Mexico, Chile and Nigeria. China’s slowdown is rippling out to countries that supply Chinese factories with components, from Indonesia to South Korea.

Between now and the end of next year, developing countries are on the hook to repay some $2.7 trillion in debt, according to a report released Monday by the U.N. trade body. In normal times, they could afford to roll most of that debt into new loans. But the abrupt exodus of money has prompted investors to charge higher rates of interest for new loans.

The U.N. body called for a $2.5 trillion rescue for developing countries — $1 trillion in loans from the International Monetary Fund, another $1 trillion in debt forgiveness from a broad range of creditors and $500 billion for health recovery.

“The great fear we have for developing countries is that the economic shocks have actually hit most of them before the health shocks have really begin to hit,” said Richard Kozul-Wright, director of the division on globalization and development strategies at the U.N. trade body in Geneva.

In the most optimistic view, the fix is already underway. China has effectively contained the virus and is beginning to get back to work, though gradually. If Chinese factories spring back to life, that will ripple out across the globe, generating demand for computer chips made in Taiwan, copper mined in Zambia and soybeans grown in Argentina.

But China’s industry is not immune to global reality. Chinese consumers are an increasingly powerful force, yet cannot spur a full recovery. If Americans are still contending with the pandemic, if South Africa cannot borrow on world markets and if Europe is in recession, that will limit the appetite for Chinese wares.

“If Chinese manufacturing comes back, who exactly are they selling to?” asked Mr. Rogoff, the economist. “How can global growth not take a long-term hit?”