Don't get me wrong, I very much enjoyed reading through all the online commentary from twenty-somethings hiding behind their Japanese-anime avatars as they waded into discussions about the United States' liquidation of Iranian top general Qassim Suleimani.

"Iran might get mad at us so we are morally compelled to leave the world's worst terrorist alive," was quite the take.

About the only thing more entertaining was the fateful decision of the popular Weight Watchers company to launch their new social media campaign #thisismyWW at the precise moment Twitter was exploding with predictions of #WWIII. Oops.

But amid all the chatter, the predictions and prophecies of what would come of the U.S. airstrike, I wonder how many have paused to consider what President Trump's decision has made incontrovertibly clear to a watching world: America's threats are no longer idle.

For those who don't remember, after Iran puppet masters like Suleimani orchestrated an attack on the U.S. Embassy in Iraq, President Trump issued this New Year's Eve message to the world:

In response, Iran's Supreme Leader Ayatollah Khamenei mocked Trump with this taunting response:

At least for this spectator observing the unfolding peeing match between the two leaders, I was left scratching my head as to why, besides arrogant pride, the Ayatollah would taunt a country with the resources and might of the United States. It really doesn't make sense – until you remember recent history.

The previous American president fostered an unfortunate foreign policy pattern of threatening "red lines" with hostile global actors. Whether it was the "red line" of Syria using chemical weapons on civilians in their civil war, the "red line" of Iran not upholding its treaty with Israel, or the "red line" of Iran not developing nuclear weapons, President Obama wasn't timid about saber-rattling to try to advance American diplomatic objectives.

There was only one consistent, nagging problem. Like a parent who relentlessly threatens a defiant child with punishment that never materializes, Obama's lack of disciplined follow-through disastrously weakened the country's credibility. He caved on Syria, and ended up airlifting $1.7 billion in unmarked bills on pallets to Iran in the middle of the night, all in an effort to make nice with the terrorist state.

It is hardly conjecture to note that many of those dollars were subsequently put to use in financing Suleimani's relentless strikes against U.S. servicemen and women in the region.

With such recent history, it's really no wonder that Iran would scoff at another U.S. threat.

It remains to be seen what Iran's next move will be as the smoke settles from the strike that killed Suleimani, though foolishly initiating the Twitter-anticipated WWIII with a superpower that could vaporize them in seconds doesn't seem likely.

What is clear, however, is that at least for now, red lines mean something again in American foreign policy.