The leaders of big banks have mostly stayed mum on the uncomfortable ideas floated lately at the Federal Reserve Bank of Minneapolis — breaking up the big banks, raising their capital requirements or treating them like utilities.

But in recent days Jamie Dimon, the boss of JPMorgan Chase, made a vigorous case for the indispensability of large financial institutions, putting forth the industry’s loudest reply yet to Minneapolis Fed President Neel Kashkari’s push to end the phenomenon of too big to fail.

The chief executive of the largest bank in the United States took time in his annual shareholders letter to enumerate the benefits of banks like his not just for American multinationals and countries around the world, but also for community banks. He mentioned neither Sen. Bernie Sanders — who has pledged to break up the big banks as part of his presidential campaign — nor Kashkari in the letter, but warned generally against picking fights with large financial institutions.

“America faces enough real challenges without inventing conflict where none need exist,” Dimon said. “Banks of all sizes do themselves and their stakeholders better service by acknowledging the specific value different types of institutions offer.”

Kashkari, who has now been president of the Minneapolis Fed for just over three months, caused a stir in February when he said he and the economists at the regional bank would come up with a plan by the end of the year for ending “too big to fail.” A first symposium was held in early April, attracting economists from across the country. A second forum will be held May 16, at which former Fed Chairman Ben Bernanke is scheduled to speak.

Executives at big banks and their national trade groups have so far not participated in Kashkari’s effort or said much publicly, though with JPMorgan Chase, Bank of America, Citigroup, Wells Fargo and U.S. Bank all slated to report their quarterly earnings in the next 10 days, executives are likely to get questions on Kashkari’s initiative.

Dimon was the first to weigh in. In the midst of his 50-page letter, Dimon’s answer to the question “Does the United States really need large banks?” took four pages.

He argued that banking as an industry accounts for a smaller share of the economy in the United States than in most large, developed nations. Also, the top five U.S. banks hold a smaller share of the nation’s banking assets than do the largest banks in other countries.

Dimon also laid out the ways big banks help the American economy. They allow public companies, many of them multinationals, to pay and get paid for goods and services all over the world. They extend lines of credit to these firms, and raise capital for them — often in multiple countries in multiple currencies.

Each day, JPMorgan Chase moves about $5 trillion, raises or lends $6 billion in capital for these firms, and buys or sells about $1.5 trillion in securities, Dimon said. The bank also helped countries raise about $60 billion in capital in 2015.

“We do all this efficiently and safely for our clients,” Dimon said. “Our size gives us the ability to make large and innovative investments that are often needed to create new products and services.”

And the community banks that are often pitted against large banks need them too, Dimon said.

Big banks buy mortgages from smaller banks, securitize the mortgages, sell them to investors and service the loans. Large banks distribute and collect physical cash for smaller banks, process their checks and clear their international payments.

JPMorgan Chase alone works with 339 small banks and 10 corporate credit unions across the country, Dimon said. In 2015, JPMorgan Chase provided smaller financial institutions with $4.7 billion in short-term credit to help with cash management, and processed $7.6 trillion in payments and receivables for them.

Given the complexity of the banker-client relationship — sometimes banks have to say no to their customers and they are always struggling to accurately price their risks — Dimon roundly rejected the idea that banks could be treated like utilities. “There is nothing about banking that remotely resembles a utility,” he said.

He lauded America’s financial system as the “finest the world has ever seen,” a global standard-setter. But he warned that American leadership is not guaranteed. Banks in other countries are striving for dominance and getting bigger.

“I do not want any American to look back in 20 years and try to figure out how and why America’s banks lost the leadership position in financial services,” Dimon said. “If not us, it will be someone else and likely a Chinese bank. Today, many Chinese banks already are larger than we are, and they continue to grow rapidly. They are ambitious, they are supported by their government and they have a competitive reason to go global — the Chinese banks are following and supporting their Chinese companies with the financial services that are required to expand abroad.”