The bigger the bailout, the higher the cost. And the already-steep price of Europe’s bailout of debt-riddled nations, including Greece, Spain and Italy, could climb even higher if the process elevates interest rates.

That’s a rising risk, according to assorted experts.

As The Wall Street Journal reported last week, banks, as “the primary buyers of Spanish and Italian government bonds no longer have much spare cash to continue such purchases.”

Thus, interest rates that had gone down are now going back up — and “rekindling investor fears about Europe’s ability to arrest the three-year-old sovereign-debt crisis and return the region to health.”

At least 800 banks have obtained emergency three-year loans from the European Union’s Central Bank (ECB) over the last five months to fund the massive debt-relief mission.

But Alan Broughton, an analyst at RBC Capital Markets, warned that “eventually the liquidity extended [by the ECB] will be fully deployed, and at that point Spanish and Italian banks will either have to stop buying sovereign bonds, removing the largest buyer from the sovereign market, or sell bonds,”

In the ominous words of the Journal story: “The cheap money has reduced the urgency with which some banks are cleaning up their balance sheets, a trend that some critics worry could delay the industry’s return to health.”

Unfortunately, many Americans, after our long and continuing run of historically low interest, have forgotten that “cheap money” isn’t necessarily in permanent supply.

The European debt mess is offering a refresher course in that and other bottom-line realities.

Lest you be tempted to ridicule the Europeans for their ongoing inability to balance their national governments’ books, keep in mind that in the modern realm of global finance, their difficulties add to ours.

Keep in mind, too, that our federal government is on track toward its fourth straight deficit of at least $1.29 trillion — each nearly tripling the previous record of $455 billion. Our sustained spending spree has increased our record national debt to $15.7 trillion.

And that European debt mess should increase our awareness of the risks that are rising along with our red-ink flood.