- Nigeria’s finances, currency connected to global dollar conditions
- Africa affected by its foreign currency financing
- Case for Nigeria to expand non-oil fx earnings
As US debt passes $40 trillion and Treasury yields climb, the consequences are moving beyond Wall Street — with higher global borrowing costs, tighter dollar liquidity and fresh risks for Nigeria.
The United States has crossed a debt threshold that would be alarming for almost any other country: $40 trillion.
But the more consequential question for investors outside America is not simply how large the US debt has become. It is what happens when the world’s biggest borrower begins competing with governments and companies everywhere else for global savings.
That is the concern behind a warning from Nigel Green, chief executive officer of deVere Group, who argues in a statement made available to Business A.M. that America’s debt dynamics have become increasingly self-reinforcing, with interest costs adding to borrowing requirements and creating a cycle that could have consequences well beyond US markets.
The US national debt crossed $40 trillion in August, according to Treasury data cited by deVere, after increasing by about $1 trillion in five months. Green argues that the mathematics of the debt burden is becoming increasingly difficult to ignore.
“This is arithmetic, not sentiment,” Green said. “Interest is compounding faster than the economy generating the revenue to pay it.”
For the rest of the world, however, the significance of America’s debt is less about whether Washington can repay its obligations and more about the price the US government has to pay to finance them — and how that price is transmitted through the global financial system.
That transmission matters enormously for emerging markets.
When America’s risk-free rate rises, everyone gets repriced
US Treasury securities sit at the foundation of the global financial system.
Their yields influence the price of mortgages, corporate bonds, sovereign debt and other assets across markets. When Treasury yields rise, the starting point for global borrowing costs moves higher.
The effect can be particularly severe for emerging economies.
A government issuing dollar-denominated debt typically pays the US Treasury yield plus a country-specific risk premium. If the Treasury benchmark rises, the borrowing cost rises before the country’s own risk is even considered.
For African governments that rely on international capital markets to finance infrastructure, fiscal deficits and refinancing needs, that can become a significant constraint.
The result is a paradox: America’s fiscal problem can increase the cost of capital for countries that had no role in creating it.
That is why the $40 trillion milestone deserves attention in Lagos as much as on Wall Street.
Nigeria sits at the end of the transmission chain
For Nigeria, the issue is particularly relevant because the country’s finances and currency remain closely connected to global dollar conditions.
A stronger dollar can increase the naira cost of servicing foreign-currency obligations. Higher global yields can make international borrowing more expensive. And when investors can obtain more attractive returns from US assets, the incentive to allocate capital to riskier emerging markets can diminish.
The chain is relatively straightforward: US borrowing rises → Treasury yields face upward pressure → global borrowing costs increase → capital becomes more selective → emerging-market currencies and bonds face pressure → Nigeria’s financing environment tightens.
Nigeria therefore does not need to own a large amount of US debt to be exposed to America’s fiscal trajectory.
Its vulnerability comes from its position in the international financial system.
This is especially important because Nigeria is simultaneously trying to deepen foreign investment, stabilise the naira, refinance obligations and fund infrastructure and economic expansion.
A more expensive global cost of capital makes all four objectives harder.
Africa’s dollar dilemma
The broader African problem is the continent’s dependence on foreign-currency financing.
Many African sovereigns borrow in dollars, euros or other major currencies while generating much of their government revenue in domestic currency.
That creates a currency mismatch. When the dollar strengthens, the domestic-currency cost of servicing dollar debt rises. When US yields rise, refinancing that debt becomes more expensive. And when international investors become more risk-averse, African borrowers may have to offer still higher yields to attract them.
The vulnerability is therefore cumulative. Higher US yields + stronger dollar + wider African risk premiums = a significantly higher cost of capital.
For countries already dealing with elevated debt-service burdens, that can crowd out spending on infrastructure, health, education and development.
It can also make governments more reluctant to borrow precisely when investment is needed to accelerate growth.
But there is an important twist
The dollar is not behaving entirely according to the textbook script.
Green points to an unusual divergence: Treasury yields have risen while the US Dollar Index has fallen.
Ordinarily, higher US yields can attract international capital and support the dollar. If investors instead begin demanding higher yields because they perceive greater fiscal or credit risk, the relationship becomes less straightforward.
That distinction could prove important. The world’s reserve currency has historically benefited from an extraordinary privilege: investors have generally regarded US government debt as the ultimate safe asset.
If that perception changes at the margin — even without a loss of confidence in US solvency — the implications could be substantial.
The issue is not necessarily a collapse of the dollar. It is whether investors begin demanding a larger premium for holding long-dated US government debt. That would represent a structural change in the global cost of money.
The AI boom adds another layer
There is also an emerging competition for the world’s available capital.
The enormous investment required to build artificial-intelligence infrastructure is generating substantial corporate borrowing. According to the deVere statement, AI infrastructure companies have issued roughly $1.5 trillion in corporate bonds this year.
That matters because governments are not borrowing in isolation.
The US Treasury, European governments, emerging-market sovereigns and highly capital-intensive corporations are effectively competing within the same global pool of savings.
If AI companies are prepared to pay attractive yields to finance data centres, semiconductor capacity and related infrastructure, sovereign borrowers may have to offer more compelling returns to attract investors.
That creates what could become an increasingly important financial-market tension: The AI investment boom needs cheap capital, while America’s debt burden is helping push the price of capital higher.
The irony is that one of the world’s biggest engines of future productivity is arriving at precisely the moment when global investors are becoming more demanding about the price of money.
Nigeria’s opportunity — and warning
For Nigeria, the lesson should not be that America is about to trigger a global financial crisis.
There is little value in predicting an imminent US debt collapse. The United States retains enormous advantages: it borrows in its own currency, controls the world’s deepest sovereign bond market and issues the currency that dominates global reserves and trade.
The more realistic risk is a prolonged period in which money remains structurally more expensive.
That is a very different problem — and one Nigeria can prepare for.
It strengthens the case for expanding non-oil foreign-exchange earnings, deepening domestic capital markets, attracting stable long-term investment rather than relying excessively on portfolio flows, maintaining adequate reserves and limiting unnecessary exposure to foreign-currency liabilities.
It also reinforces the importance of fiscal credibility. If global investors are already demanding more compensation to hold US government debt, countries with weaker credit profiles will have an even harder time persuading investors to lend cheaply.
Nigeria cannot influence America’s debt trajectory. But it can determine how vulnerable its own economy is to the consequences.
The $40 trillion question
America’s debt milestone therefore needs to be viewed as more than a Washington fiscal story. It is a story about the global price of money.
If the world’s largest borrower has to pay increasingly higher rates to finance an expanding debt stock, those higher rates do not remain confined to the US Treasury market.
They travel through currencies, bonds, equities, corporate financing and sovereign debt markets.
They eventually reach Lagos. And that leaves investors and policymakers with a question that is arguably more important than whether US debt reaches $45 trillion or $50 trillion:
If America — the world’s benchmark borrower — has to pay more for money, how much more will everyone else have to pay?




