ZURICH—The chairman of Switzerland’s largest bank received an urgent call last week. On the other end were three top Swiss officials who delivered an ultimatum dressed up as a proposal. UBS Group AG needed to rescue its failing rival, Credit Suisse Group AG.

For any country, it would be a financial emergency. For Switzerland, the stakes verged on existential. Its economic model and national identity, cultivated over centuries, were built on safeguarding the world’s wealth. It wasn’t just about a bank. Switzerland itself needed rescuing.

It was Thursday, barely 24 hours into an escalating banking crisis and Credit Suisse was haemorrhaging deposits. The 167-year-old national institution appeared days away from bankruptcy. To keep it alive until the weekend, the central bank was about to quadruple a credit line of more than $50 billion. U.S. and U.K. regulators called their Swiss counterparts to make sure they didn’t let Credit Suisse bring down global markets.

Finance Minister Karin Keller-Sutter, central bank head Thomas Jordan and financial regulator Marlene Amstad had dialled Colm Kelleher, the UBS chairman, to present two options that were really only one: Buy Credit Suisse without a chance to fully understand its vast and complicated balance sheet—or let it fold in a protracted unraveling that UBS’s own executives worried could shatter Switzerland’s credibility as a global banking center.

Over WhatsApp, Swiss diplomats asked each other nervously whether they should move their deposits from Credit Suisse.

After a series of frantic calls and government-orchestrated meetings in Bern, UBS agreed to swallow Credit Suisse for $3.2 billion. To seal the deal, the government, which had vowed after the 2008 crisis never again to use public money to save a bank, hastily used emergency laws to do exactly that.

“Credit Suisse is not only a Swiss company. It is part of the Swiss identity,” said Thierry Burkart, head of the right-wing Liberals party, the country’s third largest. “The bankruptcy of a global Swiss bank would have had an immediate effect everywhere. There would be long and hard reputational damage for Switzerland,” he said.

The swift demise of Switzerland’s second-largest lender has rattled financial markets, and added a global dimension to a banking crisis that broke out on the West coast of the U.S. with the failure of Silicon Valley Bank.

It is still far from clear whether the Swiss have fully contained the damage. Having two world-class banks was seen as a fail-safe to maintain Switzerland’s position in world markets. The forced marriage has left it with one and has shaken ordinary Swiss people and their faith in the country’s economic and political model.

“If Swiss banking means one huge bank, what if something goes wrong with that?” said Mark Pieth, a former head of the Organization for Economic Cooperation and Development’s bribery division who is now at the Basel Institute on Governance. “Then the entire country and its financial stability is at stake. It’s very un-Swiss.”

The central bank and finance ministry, as well as Finma, the top financial regulator in Switzerland, didn’t comment beyond their previous public statements. Bankers and Swiss officials involved in the talks, as well as Swiss and other Western diplomats, provided details of the rescue.

This Alpine nation has seen itself as a special case in Europe: a neutral broker and soberly governed democracy whose banks offer a discreet safe haven to far-flung investors and the world’s wealthy. Its banking system is five times the size of its gross domestic product and larger than in most economies. UBS combined with Credit Suisse has a balance sheet twice the size of the Swiss economy.

For years, Swiss exceptionalism has been chipped away. After 2008, the U.S. enacted laws requiring Swiss banks to transfer information about American clients to the Internal Revenue Service, a hammer blow to its banking secrecy.

Relations with the European Union, whose biggest powers surround the landlocked Alpine nation, are strained after Switzerland walked away from years long talks to bind it more closely to the trading bloc.

It is struggling to defend its 200-year-old policy of neutrality in the face of Russia’s war with Ukraine. Moscow last year put Switzerland on its “Unfriendly Countries List” after the landlocked nation, pressured by its larger neighbours and the Biden administration, joined European Union sanctions against Vladimir Putin and his closest allies.

By the same token, the country has refused to grant permission for Germany, Spain or Denmark to export Swiss military equipment into Ukraine, prompting a debate over whether Switzerland’s attachment to neutrality is damaging its reputation in Europe.

The country—once the indispensable meeting ground where great powers negotiated the end of conflicts—has been sidelined as a mediator in the Ukraine conflict by Turkey. Decades of economic and diplomatic ties to Russia have gone cold in Moscow yet become liabilities within the West.

“We have now a dilemma, a big challenge for Switzerland to be recognised as a strategic partner,” said former Swiss President Micheline Calmy-Rey. “For the time being it is not, and we are in shock.”

The U.S. ambassador last week said Switzerland was facing its most serious crisis since World War II. Foreign investors burned by Credit Suisse’s demise are rethinking their willingness to invest.

“Everything here was avoidable. We were told last week that everything was fine,” said Roger Köppel, editor of the weekly magazine Die Weltwoche and member of the right-wing Swiss People’s Party. “Reality is back and is hitting Switzerland very hard.”

Credit Suisse’s founder, Alfred Escher, was an industrial godfather of modern Switzerland. The businessman and politician used the lender to underwrite Switzerland’s rail lines, tunnelling through the Alps to connect the mountain-encircled nation with the rest of Europe.

Stretching back to Nazi gold, Credit Suisse had harboured money for suspect clients alongside an A-list roster of billionaires, sovereign-wealth funds and families. In a 2014 settlement with the U.S. Justice Department, the bank paid $2.6 billion and admitted its bankers had hand delivered cash and destroyed documents to help Americans hide untaxed wealth.

A banker in London took bribes to make loans in Mozambique. Another forged client signatures and lost them hundreds of millions of dollars. More recently, in 2021, Credit Suisse lost more than $5 billion when family office Archegos Capital Management collapsed, marking the start of its tumble into UBS.

Through the scandals, Swiss banks, and even Credit Suisse, still retained their image as fortresses for the rich.

The latest Credit Suisse management team included several who joined from UBS, including Chairman Axel Lehmann and Chief Executive Ulrich Körner. They made fresh pledges to clean up and saw returning Credit Suisse to health as a form of national service, people familiar with their thinking said.

Even after raising $4 billion capital late last year for a deeper restructuring, Credit Suisse traded at just 20% of its book value. Customers pulled $120 billion from the bank last fall during an internet frenzy over the bank’s health.

Not far from Credit Suisse in central Zurich, executives at UBS prepared just in case they were called on to help. For years, UBS executives and management consultants had mapped out scenarios and what UBS would require from the government, as a precaution.

UBS owed the government. It had been Switzerland’s problem child before.

The result of a merger in the late 1990s between Swiss Bank Corp. and Union Bank of Switzerland, UBS grew rapidly in the banking boom of the 2000s, opening a trading floor bigger than a football field in Stamford, Conn. It needed a Swiss government bailout in the 2008 financial crisis for losses on toxic securities. Chastened, it pulled back from trading and focused on managing wealth.

The Credit Suisse chairman and CEO had feared the call from Swiss authorities.

The bank’s stock had gone into free fall after the chairman of the bank’s biggest investor, Saudi National Bank, speaking in a television interview at a finance conference in Riyadh, said it wouldn’t invest more in Credit Suisse: “Absolutely not,” he said, citing rules on bank ownership, since Saudi National Bank already owned 9.9%.

What the market heard was that Credit Suisse’s largest shareholder wouldn’t back it. Mr. Lehmann, at the same Riyadh conference, rushed back to Zurich. Credit Suisse appealed to the Swiss National Bank and Finma to calm the markets with a message of support.

That Wednesday night, Credit Suisse received a more-than $50 billion liquidity line from the central bank, and the regulators said it met Swiss capital and liquidity requirements.

Credit Suisse customers kept pulling deposits Thursday. Authorities moved to make more than $150 billion in additional liquidity available to the bank, Ms. Keller-Sutter, the finance minister, said. The government didn’t disclose the move, hoping to keep Credit Suisse alive until the weekend, when a permanent solution could be found.

Stung by having to rescue UBS before, Swiss authorities had a plan to handle big banks if they fell under stress. To avoid tapping taxpayer money, the country’s financial regulator would swiftly impose losses as needed on shareholders and bondholders.

That solution was discarded for Credit Suisse, as authorities feared it would cause panic among bank investors around the world, Mr. Jordan, the central bank governor, said Sunday.

UBS Chairman Colm Kelleher got his call Thursday from the Swiss officials, a tripartite representing Finma, the Swiss National Bank and the finance minister. The message was clear: UBS would take over Credit Suisse, or the latter would go bankrupt, potentially bringing down UBS and other banks in the fallout.

Irish-born Mr. Kelleher joined UBS as chairman in April, after a long career at Morgan Stanley, including as chief financial officer in the 2008 financial crisis. His team swung into action, helped by a blueprint developed under former UBS Chairman Axel Weber on what a combined UBS-Credit Suisse could look like.

The UBS and Credit Suisse chairmen and CEOs had a quick meeting with the finance minister Friday at UBS, where they were told they would sign a deal by Sunday.

Credit Suisse’s large shareholders in the Gulf, including Saudi National Bank, worried they were about to lose their entire investment. They called Swiss officials, including the central bank governor and government ministers, and wrote letters, arguing that their rights were at risk of being trampled on, and that they might be able to come up with a better deal.

On Saturday evening, Mr. Kelleher took a break from dinner to call Mr. Lehmann with a $1 billion offer. It was less than Saudi National Bank’s investment for one-tenth of the bank in November, a deal Mr. Lehmann brokered.

On the Credit Suisse side, executives fretted whether they could get a deal through their shareholders. A quarter of the shares were held by a trio of Gulf investors. The government had a solution. It passed a law that allowed a deal to pass without a shareholder vote. A government official read out the new law to Credit Suisse executives, without giving them it in writing, according to people familiar with the matter.

Sunday morning, the Gulf shareholders Qatar Investment Authority and Olayan Group, and the Saudi Public Investment Fund, part-owner of Saudi National Bank, made a last-ditch proposal to Credit Suisse’s board. They would inject around $5 billion, keep the stable Swiss bank and sell off other parts over time.

Mr. Lehmann put a call into the Swiss finance minister. UBS is the only option, he was told, and the line went dead.

Swiss officials from the get-go would only consider a Swiss option to save Credit Suisse, people familiar with the matter said. They shot-down an informal approach from U.S. asset management giant BlackRock, Inc. to get involved, these people said.

Credit Suisse’s board dug in its heels on the low price. With the announcement hours away, Swiss officials told UBS to try harder.

Late Sunday afternoon, UBS agreed to lift its offer and pay a little over $3 billion—less than half Credit Suisse’s market value on Friday. Crucially, Swiss regulators would write off $17 billion on the riskiest type of Credit Suisse bonds. The market for these bonds, commonly issued by European banks, was severely hit Monday. UBS would also get a more than $200 billion liquidity line from the central bank, and a government guarantee of over $9 billion against some potential losses.

To get the deal done, the government waived antitrust laws on the grounds that financial stability was at stake.

“Any other solution would really have triggered a financial crisis,” said Ms. Keller-Sutter, the finance minister.

At a Sunday news conference announcing the deal, Mr. Kelleher said UBS buying Credit Suisse was in the best interest of Switzerland.

—Ben Dummett, Julie Steinberg and Summer Said contributed to this article.

The Federal Reserve approved another quarter-percentage-point interest-rate increase but signalled that banking-system turmoil might end its rate-rise campaign sooner than seemed likely two weeks ago.

The decision Wednesday marked the Fed’s ninth consecutive rate increase aimed at battling inflation over the past year. It will bring its benchmark federal-funds rate to a range between 4.75% and 5%, the highest level since September 2007.

Officials sent a hint that they might be done raising interest rates soon in their post meeting policy statement. “The committee anticipates that some additional policy firming may be appropriate,” the statement said. Officials dropped a phrase used in their previous eight statements that said the committee anticipated “ongoing increases” in rates would be appropriate.

The policy statement said it was too soon to tell how much recent banking stress would slow the economy. “The U.S. banking system is sound and resilient,” the statement said. “Recent developments are likely to result in tighter credit conditions for households and businesses and to weigh on economic activity, hiring, and inflation. The extent of these effects is uncertain.”

All 11 voters on the rate-setting Federal Open Market Committee agreed to the decision.

New projections showed 17 out of 18 officials who participated in the meeting expect the fed-funds rate to rise to at least 5.1% and to stay there through December, implying one more quarter-point increase. The quarterly projections were little changed from those released in December.

Fed officials have at times over the past year acknowledged the risk of being forced to simultaneously fight two problems—financial instability and inflation. Several have said they would use emergency lending tools, along the lines of those unveiled this month, to stabilise credit markets so they could continue to raise interest rates or hold rates at higher levels to combat inflation.

At a news conference after the decision, Fed Chair Jerome Powell said officials had considered holding rates steady but opted to raise them given signs of still-high inflation and economic activity.

Various estimates of how much the banking stress could slow the economy amount to “guesswork, almost, at this point,” Mr. Powell said. “But we think it’s potentially quite real. And that argues for being alert as we go forward.”

That turmoil offers the strongest evidence yet of spillovers from higher interest rates to the broader economy. The upheaval has served as a stiff reminder of the perils Fed officials, regulators, lawmakers and the White House face trying to corral inflation that soared to a 40-year high last year.

U.S. policy makers cushioned the economic shock created by the Covid-19 pandemic in 2020 and 2021 by providing extensive financial aid and cheap money. Congress and the White House have largely delegated to the Fed the task of taming price pressures.

The fed-funds rate influences other borrowing costs throughout the economy, including rates on mortgages, credit cards and auto loans. The Fed has been raising rates to cool inflation by slowing economic growth. It believes those policy moves work through markets by tightening financial conditions, such as by raising borrowing costs or lowering prices of stocks and other assets.

Two weeks ago, Mr. Powell suggested officials would debate whether to raise rates by a quarter-point or a bigger half-point after reports showed hiring, spending and inflation were stronger early this year than they thought at the time of their Jan. 31-Feb. 1 meeting. “Nothing about the data suggests to me that we’ve tightened too much,” he said on March 7 before the Senate Banking Committee.

An astonishing run on the $200 billion Silicon Valley Bank changed everything. SVB’s depositors were heavily concentrated in the tight knit world of venture capital and startup firms, which were burning cash and withdrawing deposits as the once-highflying technology sector cooled.

On March 8, SVB said it was looking to raise capital from investors and that it would record a loss on longer-dated securities whose values had fallen as interest rates shot up. Nearly a quarter of the bank’s deposits fled over the next day and the bank was taken over by regulators on March 10.

To avoid a broader panic, federal authorities guaranteed the uninsured deposits of the California lender and a second institution, New York’s Signature Bank. The Fed also began offering loans of up to one year to banks on more generous terms as a precaution.

Banking-sector tremors are likely to lead to a pullback in lending because banks will face increased scrutiny from bank examiners and their own management teams to reduce risk taking. Banks could also see earnings squeezed if they feel pressure to raise deposit rates, which could further crimp lending.

That would mean fewer loans to consumers to buy cars, boats, homes and other big-ticket items, and less credit for businesses to hire, expand or invest, raising the risk of a steeper economic downturn.

Banks with fewer than $250 billion in assets account for roughly 50% of U.S. commercial and industrial lending, 60% of residential real estate lending, 80% of commercial real estate lending, and 45% of consumer lending, according to Goldman Sachs.

“I think we’re looking at a sizeable credit crunch,” said Daleep Singh, a former executive at the New York Fed who is now chief global economist at PGIM Fixed Income.

Since officials’ previous meeting, the economy had shown surprising strength, leading to concerns that aggressive rate rises over the previous year hadn’t done enough to slow the economy and lower inflation. Central bankers are concerned that prices will keep rising rapidly if consumers and businesses expect them to.

Inflation fell to 4.7% in January from 5.2% in September, as measured by the 12-month change in the personal-consumption expenditures price index excluding food and energy, the Fed’s preferred gauge. Economists expect the government to report next week that the inflation rate was unchanged in February.

Banking stress had led to questions in the past week over whether the Fed would even raise rates at all.

Some analysts fretted that a timeout on rate rises would risk so-called financial dominance, in which monetary policy becomes overly focused on avoiding market stress to the detriment of fighting inflation. A big market rally, in which stock prices rise and borrowing costs fall, could spur more demand and fan price pressures.

“They’d like to avoid that,” said William English, a former senior Fed economist who is a professor at Yale School of Management.

Others said the Fed would have been hard-pressed not to raise interest rates given recent strength in the economy and aggressive measures taken to shore up confidence in the banking system.

“Right now pausing would cause disruption,” said Donald Kohn, a former Fed vice chair. Deciding against raising rates would “signal that they don’t have confidence in their financial stability tools.”

Jan Hatzius, chief economist at Goldman Sachs, disagreed. It would have been better for the Fed to move cautiously given the highly uncertain environment that resulted from the banking stress, he said. “If more issues crop up after Wednesday, that’s also not going to be very confidence inspiring,” he said.

Fed officials have tried to signal their interest-rate moves deliberately over the past year to avoid the kind of market turmoil set off in 1994, when the Fed doubled its short-term benchmark rate from 3% to 6% in a 12-month span.

That rapid tightening hammered stocks and bonds and indirectly contributed to the demise of Kidder Peabody & Co., the bankruptcy of Orange County, Calif., and Mexico’s peso devaluation, which required a bailout from the U.S. and the International Monetary Fund.

After skipping on a rate increase in December 1994, as the peso crisis intensified, the Fed made a final rate increase in early 1995.