Uh oh … more bad political news out of Europe.

Portugal’s government is at risk of falling, as two key ministers resigned in protest over the EU’s mandated austerity policies. This follows a massive protest in Greece after budget cuts forced the government to shut down the bloated state broadcaster (and fire all of its employees) and the conviction and sentencing of former Italy prime minister Silvio Berlusconi on sex and abuse of power charges.

So, is it time to start worrying about Europe again?

No — or at least not yet.

The Portugal developments are a little worrying but not exactly unexpected. This is politics, and if the Portuguese believe they get a better deal by challenging their creditors by taking this to the brink, then that is exactly what they will do.

Spain and Ireland also are negotiating a retroactive bank bailout that would shift the debts taken on to the EU’s bank bailout mechanism and off of Ireland and Spain’s governments. Negotiations are still dragging on … and I don’t expect a definitive conclusion this year.

All of that is fine and good, but surely there will come a point to panic, right?

Maybe. And that is why I am watching Spain and Italy’s 10-year bond yields (charts below):

Spanish and Italian bond yields have been trending downward for the past year. If you might recall, ECB President Mario Draghi made his now infamous “do whatever it takes” comments almost exactly a year ago, and they had the desired effect. Except for a brief blip in February, yields have been falling almost continuously. Until now.

Starting in May, Italian and Spanish bond yields have started to creep up again. Spain’s 10-year yield briefly popped over the psychologically important 5% mark last month, and Italy’s came close.

Is this cause for concern? At first glance, I would say yes. But let’s keep it in context. Virtually all yields everywhere in the world rose in May and June over fears that the Federal Reserve would be tapering its quantitative easing programs. But once the dust settled, it became obvious very quickly that the bond market had jumped the gun. The tapering — if it happens — is still six to 12 months away. And even when it does come, it likely won’t be as harsh as the bond bears fear.

That’s nice, but what does it mean for Spain and Italy, and when do we panic?

This will be the signal for me: If yields in the U.S. and Germany continue to drift lower, but Italian and Spanish yields rise, that divergence would get my attention. It wouldn’t mean that a crisis was imminent, but it would mean that the bond market had lost confidence in the eurozone again and that Draghi’s “whatever it takes” is simply not enough.

I don’t see that happening, and I am viewing any dips in the prices of European stocks as buying opportunities.

But if I’m wrong — and Spanish and Italian yields shoot above 5% again — it will be time to take a little risk off the table and get at least partially defensive.

Charles Lewis Sizemore, CFA, is the chief investment officer of the investment firm Sizemore Capital Management.  As of this writing, he did not hold a position in any of the aforementioned securities. Click here to receive his FREE 8-part investing series that will not only show you which sectors will soar but also which stocks will deliver the highest returns. The series starts November 5 and includes a FREE copy of his 2014 Macro Trend Profit Report.