The ever-growing world debt has reached a record level of $307 trillion. The United States, Italy and Britain are of greatest concern, more than 20 leading economists, former politicians and major investors told Reuters.

In their view, sound spending plans, tax increases and economic growth could prevent the harbinger of another economic crisis in the next decade.

More than 80 percent of the $10,000 increase in global debt in the first half of the year came from advanced economies, according to the Institute of International Finance.

Record levels of debt, high interest rates, costs related to climate change, an aging population, health care and pension costs are fueling fears of a possible crisis in financial markets in the world’s largest economies.

“We are not far from a crisis of public finances”

Peter Pret, former chief economist at the European Central Bank (ECB), said that while debt still appeared acceptable, the outlook was worrying given long-term spending needs.

“You can take many countries today and you will see that we are not far from a crisis of public finances,” said Praet, who joined the ECB during the 2011 debt crisis.

“If there’s an accident or a combination of events, we’re going to enter some kind of adverse dynamic, which is a real possibility,” he added.

Strong funding needs and the withdrawal of central bank support add to price uncertainty for investors, said Sofia Drossos, chief economist at hedge fund Point72 Asset Management.

“The deficit and the level of debt make us feel uncomfortable,” said Daniel Ivasin, PIMCO’s chief investment officer, who is reluctant to hold long-term bonds, according to Reuters.

Looking ahead, “sovereign debt trajectories pose the greatest threat to macroeconomic and financial stability,” said Claudio Borio, head of monetary and economic affairs at the Bank for International Settlements and Stability.

Debt approaches or exceeds 100% of GDP in the UK, US and Italy

Olivier Blanchard, a senior fellow at the Peterson Institute for International Economics, was most concerned about the United States because of its “compromising political budget process” and high primary deficit.

“How will it end? I would argue not by default, but when markets start to reflect their concerns in Treasury quotes due to the political crisis and a potentially sharp adjustment,” said the former IMF chief economist.

Ray Dalio of the hedge fund Bridgewater Associates expects a debt crisis in the United States.

A spokesman for the US Treasury Department highlighted Secretary Janet Yellen’s recent statements regarding the budget deficit and rate hikes. Yellen told the Wall Street Journal last week that the administration is committed to “sustainable fiscal policy” and that the budget can be adjusted to ensure that.

On the other hand, experts warn, Italy’s 2.4 trillion euro debt is in the spotlight in Europe, where the IMF has said that high debts are putting governments at risk of crises.

Scope Ratings has warned that Italy may not be eligible for the ECB’s massive bond-buying program.

Again, Rome’s rising debt-to-GDP ratio will make a downgrade more likely. This will have “significant implications” for southern Europe, said Jim Leaviss of M&G Investments.

Economy Minister Giancarlo Giorgetti said he was not afraid of a downgrade but could not rule it out, while the institution he represents declined to comment on the matter.

Slow economic growth is keeping Italy’s debt high, a risk for Europe and Britain, where austerity plans will reduce public investment.

“Unless we have better growth prospects in Europe, the math for debt sustainability looks pretty weak,” said Daylip Singh, chief global economist at PGIM Fixed Income and a former adviser to US President Joe Biden.

Britain’s Treasury has said it is on track to reduce debt and grow the economy with major reforms.

If we continue like this, we will have a crisis

Effective spending, reforms and growth plans are key, according to Reuters. “We need more investment, not less,” said Professor Jonathan Ports of King’s College London, Britain’s chief cabinet economist during the financial crisis.

Borrowing is more difficult when interest rates are high, so governments need to have reliable plans. The EU is overhauling its tax rules, and Britain’s Labor Party is promising to legislate for the Office for Budget Responsibility’s reforms of taxes and spending plans.

Although unpopular, tax increases, particularly in the United States and Britain, and imminent spending cuts are necessary, economists cited by Reuters said, adding that delaying the move would hurt governments’ ability to respond to future shocks.

“If we continue to move forward the way we are doing now, we will see a crisis in the next decade,” said Moritz Kremer, chief economist at LBBW, who has watched S&P’s European sovereign ratings decline since 2011.