Risk gathers where financing has little room to bend.

Why is foreign-currency debt a vulnerability?

A government that owes dollars, euros or another foreign currency cannot create that currency through its own central bank. If its domestic currency falls, the local-currency value of the obligation rises. Export receipts, foreign-exchange reserves and access to external finance then become central to repayment capacity.

This is why two countries with the same debt-to-GDP ratio can face very different risks. Domestic-currency debt can still be difficult to service, especially when inflation is high. Foreign-currency debt adds a conversion problem at exactly the point confidence may be weakening.

What does rollover risk look like?

Debt that matures soon must be refinanced soon. A government can be solvent over a long horizon yet face immediate strain if it cannot sell new securities to replace old ones at workable rates. Short-term debt lowers interest costs in calm conditions but exposes the issuer to rapid repricing when policy rates or risk premiums rise.

Debt managers attempt to spread maturities, maintain regular issuance and build a reliable investor base. These measures reduce concentration, but no schedule eliminates the possibility of a shock. The relevant comparison is the size of near-term funding needs relative to market depth, reserves and fiscal flexibility.

How does fiscal capacity affect debt?

Debt service is paid from public resources. A broad and effective tax base, predictable administration and realistic spending control can support a larger debt burden than a narrow or volatile revenue base. Commodity-dependent revenues may rise sharply and then fall sharply; a ratio calculated at the top of a cycle can give a misleading sense of room.

The primary balance helps identify whether the government’s current revenues cover non-interest spending. A primary surplus can stabilise debt, but the required adjustment may be politically and economically difficult. Severe austerity can itself reduce output and tax receipts, which is why debt adjustment is not merely an accounting exercise.

Why do institutions and credibility matter?

Reliable statistics, an independent central bank, a functioning legal system and transparent debt reporting make it easier for investors and citizens to assess obligations. That does not guarantee low borrowing costs. It reduces uncertainty about who owes what, under which law and with what repayment process.

Risk is therefore a system of relationships. A debt ratio is one signal; the funding currency, maturity schedule, economic base and institutional response capacity explain why that signal can mean more in one country than another.