There should be no doubt that Vladimir Putin’s regime tried to interfere in our elections and attempted to subvert our democracy.

We must respond to this unprecedented intrusion decisively—and in a manner that will make Russia think twice about doing it again.

But even more importantly, we should recognize that weakness invites aggression.

These hacks were the culmination of a failed foreign policy, namely the Obama administration’s blindness to the threat from Moscow and unwillingness to deter our adversaries.

There is an important lesson here for future presidents: if we do not shape the world around us, we will be shaped by it. That is why we need to project strength to protect our homeland.

Recall President Obama’s response to Mitt Romney’s assertion in the 2012 presidential debates that Russia was our “number one geopolitical foe.”

“The 1980s are now calling to ask for their foreign policy back,” Obama scoffed at Mr. Romney. “The Cold War’s been over for 20 years.”

That combination—of willful ignorance and hesitation—is the bedrock of the Obama administration’s “look-the-other-way” national security strategy. And look where it got us.

When the Russians invaded our ally, Ukraine, Obama refused to arm them to rebuff the illegal incursion.

Putin himself must have been surprised by the muted response.

A year later, Russia brazenly intervened in Syria to turn the tide of war in favor of a brutal, anti-America despot slaughtering his own people. Again, Obama faltered.

Now the situation in Syria looks more intractable than ever, and we’ve lost most of our leverage.

President Obama defends his foreign policy approach as “strategic patience.” But when the leader of the free world stands on the sidelines, our allies and our adversaries see only weakness.

Make no mistake: Putin was emboldened by American indecision, which is why he felt confident enough to intrude in our democratic process.

The seriousness of Russian meddling transcends party lines. Moscow’s efforts may have disproportionately targeted Democrats, but next time it could just as easily be Republicans.

Either way, it cannot be tolerated.

Yet instead of responding, Obama administration aides appear more focused on mocking President-elect Donald Trump for expressing uncertainty about the hacking claims.

But this isn’t about Mr. Trump, who was not commander-in-chief when these intrusions took place.

The man sitting in the Oval Office during this crisis was Barack Obama, who received a stream of sensitive updates on the hacks throughout the general election and had the power to take action.

So why did he do nothing? This is the real scandal.

President Obama failed to deter Russian aggression time and again, and so far, he has been negligent in responding to it right here at home.

In fact, despite knowing Russia was trying to interfere in our election months ago, he waited until weeks afterwards—once his candidate was defeated—to even offer strong words about a potential U.S. response.

The delay is disturbing.

When I was first briefed on this behind closed doors, I urged administration officials to start pushing back against Moscow. But they demurred.

As a result, the Putin regime has learned there are no consequences for their actions.

There is an important lesson here for future presidents: if we do not shape the world around us, we will be shaped by it. That is why we need to project strength to protect our homeland.

We must immediately restore American power to deter adversaries like Russia from taking advantage of us.

We also cannot hesitate to advance U.S. interests abroad, nor should we apologize for it.

While there is always a chance that our actions will cause backlash, it is guaranteed that inaction will create a world that is more dangerous for America.

Sadly, Obama’s hesitation has taught our foes a very different lesson: America can be bullied, our elections can be targeted, and our democracy is open to attack by feckless despots.

That is the staggering price of “strategic patience.”