John Kerry put on quite a war dance in the Senate on Tuesday.

The Secretary of State, backed up by Defense Secretary Chuck Hagel and Joint Chiefs Chairman Martin Dempsey, went before the Foreign Relations Committee to urge senators to support the newly drafted resolution giving President Obama authorization to use airstrikes in Syria.

Kerry made some impressive arguments in favor of military action.

He said the evidence is undeniable that Assad’s military forces used chemical weapons to kill nearly 1,500 men, women and children in Damascus.

He said that if the United States does not act to punish Assad it will send the wrong message to every rogue regime in the world.

And at one point, cranking up the rhetoric, Kerry said, “This is not the time for armchair isolationism. This is not the time to be spectators to slaughter.”

At about this point in the proceedings, I began to wonder if Kerry’s talking points had been written by George W. Bush.

When I closed my eyes, I swear I heard the voices of Colin Powell, Dick Cheney and Donald Rumsfeld explaining why the United States had a moral duty to invade Iraq and take out Saddam Hussein.

Kerry’s running argument with Sen. Rand Paul of Kentucky about whether the Obama administration was going to go to war even if Congress didn’t give its permission brought me back to 2013 — and reminded me how horribly President Obama’s indecisiveness has botched Syria.

Let’s say everything Kerry said the other day about Assad being responsible for the gas attack and the importance of the civilized world punishing him is true.

Let’s say President Obama is not playing some cynical political game with Congress, or trying to win points with the public, and that he knows every single claim Kerry made is absolutely true.

Then what is the president waiting for? Why in God’s holy name hasn’t Obama already kicked Assad’s butt?

Two weeks after Assad gassed his own people and crossed the president’s imaginary red line, we’re still debating in Congress and worrying if Vladimir Putin will get mad at us if we beat Russia’s favorite Middle Eastern pet.

As I said last week, President Obama should have done the same thing in Syria that President Ronald Reagan did in Libya when he had to wise-up Gadhafi about the cost of waging his terrorism campaign against the West.

My father acted the way the president of the United States should act — decisively. He made no calls to the United Nations asking for permission to bomb Libya.

He orchestrated no debates in Congress. He acted with resolve and ordered bombs to be dropped, not coalitions to be formed or opinion polls to be taken.

Long before Assad had a chance to launch a poison gas attack, our cut-rate commander-in-chief should have ordered a few cruise missiles fired at Assad’s head to get his full attention — or better yet, kill him.

It’s too late for such presidential decisiveness now. President Obama needed to show Assad that he — and the United States — meant business a long time ago.

But his administration dithered for more than two years, and 100,000 Syrians died in a civil war that now has so many rebel factions no one can tell the good guys from the bad.

Sen. Lindsey Graham was right when he said this week that it’s already too late for the United States to come up with a Syria strategy. He said our best options already are in our rear-view mirror.

At this point, all we can do is drop some leaflets on Damascus telling the Syrians how sorry we are that we have a president who still can’t get his act together.

Michael Reagan is the son of President Ronald Reagan, a political consultant, and the author of “The New Reagan Revolution”