SIOUX CITY, Iowa — Turn on the TV for 10 or 15 minutes here, and the ads for Republican candidates will start to blend into each other. The late-starting air wars have been dominated by foreign policy, with each new spot portraying a darker vision of the world. Each spot made at least a little news when it launched; watched in a block, between plays of a football game or reports on local news, the effect is striking.

In one heavily-rotated ad, Sen. Marco Rubio (R-Fla.), standing in front of a fluttering American flag, says President Obama has been out-played by “a lunatic in North Korea” and “a gangster in Moscow.”

In a rival ad from a pro-Jeb Bush super PAC, Right to Rise USA — which often plays in the same commercial block — voters see footage of terrorism and (less pulse-poundingly) Senate hearings as a narrator informs them that Rubio skipped key national security meetings to raise money.

A widely-played Ted Cruz ad accuses Rubio and most other Republicans of backing a plan to “admit Syrian refugees, including ISIS terrorists,” referring to the Islamic State by one of its other names.

The first ad from former Pennsylvania senator Rick Santorum, which debuted on Monday, portrays Cruz as a do-nothing while reminding voters that Santorum, the 2012 Iowa caucus winner, fought to “rebuild our military” and fight “today’s threats.”

That's what the airwaves looked like before Donald Trump announced his six-figure buy in the state:

Not every Republican is playing along. Sen. Rand Paul (R-Ky.), whose non-interventionist views have marginalized him in the wake of Paris, said that the fearmongering might be just a temporary overreaction. He has not gone on the air in Iowa; he has no intention of fulminating about terrorism.

“Polls go up and down depending on current events,” said Paul. Referring to a poll that asked voters if the fictional city from Disney’s “Aladdin” posed a security threat, Paul said, “a third of Republicans want to bomb Agraba. The good news is — two thirds don’t!”

But that's the debate among the Republicans. Strikingly, there’s no such debate on the Democratic side — not on TV. The most widely-seen ads for Bernie Sanders and Hillary Clinton focus on domestic policy and economic fairness. Here, for example, are two that ran during the same Green Bay Packers/Minnesota Vikings game that featured the Republican ads above.

Clinton’s vote for the Iraq War, which helped then-underdog Barack Obama defeat her here in the 2008 caucuses, is never mentioned at all.