With his Sunday tweet that Bashar Assad, “Animal Assad,” ordered a gas attack on Syrian civilians, and Vladimir Putin was morally complicit in the atrocity, President Donald Trump just painted himself and us into a corner.

“Many dead, including women and children, in mindless CHEMICAL attack in Syria,” tweeted Trump, “President Putin, Russia and Iran are responsible for backing Animal Assad. Big price… to pay.”

“Big price… to pay,” said the president.

Now, either Trump launches an attack that could drag us deeper into a seven-year civil war from which he promised to extricate us last week, or Trump is mocked as being a man of bluster and bluff.

For Trump Sunday accused Barack Obama of being a weakling for failing to strike Syria after an earlier chemical attack.

“If President Obama had crossed his stated Red Line In The Sand,” Trump tweeted, “the Syrian disaster would have ended long ago! Animal Assad would have been history!”

Trump’s credibility is now on the line and he is being goaded by the war hawks to man up. Sunday, John McCain implied that Trump’s comments about leaving Syria “very soon” actually “emboldened” Assad:

“President Trump last week signaled to the world that the United States would prematurely withdraw from Syria. Bashar Assad and his Russian and Iranian backers have heard him, and emboldened by American inaction, Assad has reportedly launched another chemical attack against innocent men, women and children, this time in Douma.”

Pronouncing Assad a “war criminal,” Lindsey Graham said Sunday the entire Syrian air force should be destroyed.

So massive an attack would be an act of war against a nation that has not attacked us and does not threaten us. Hence, Congress, prior to such an attack, should pass a resolution authorizing a U.S. war on Syria.

And, as Congress does, it can debate our objectives in this new war, and how many men, casualties and years will be required to defeat the coalition of Syria, Russia, Hezbollah, Iran, and the allied Shiite militias from the Near East.

On John Bolton’s first day as national security adviser, Trump is being pushed to embrace a policy of Cold War confrontation with Russia and a U.S. war with Syria. Yet candidate Trump campaigned against both.

The War Party that was repudiated in 2016 appears to be back in the saddle. But before he makes good on that threat of a “big price… to pay,” Trump should ask his advisers what comes after the attack on Syria.

Lest we forget, there was a reason Obama did not strike Syria for a previous gas attack. Americans rose up as one and said we do not want another Middle East war.

When John Kerry went to Capitol Hill for authorization, Congress, sensing the national mood, declined to support any such attack.

Trump’s strike, a year ago, with 59 cruise missiles, on the air base that allegedly launched a sarin gas attack, was supported only because Trump was new in office and the strike was not seen as the beginning of a longer and deeper involvement in a war Americans did not want to fight.

Does Trump believe that his political base is more up for a major U.S. war in Syria today than it was then?

The folks who cheered Trump a week ago when he said we were getting out of Syria, will they cheer him if he announces that we are going deeper in?

Before any U.S. attack, Trump should make sure there is more hard evidence that Assad launched this poison gas attack than there is that Russia launched that poison gas attack in Salisbury, England.

One month after that attack, which Prime Minister Theresa May ascribed to Russia and Foreign Minister Boris Johnson laid at the feet of Putin himself, questions have arisen:

If the nerve agent used, Novichok, was of a military variety so deadly it could kill any who came near, why is no one dead from it?

Both the target, Sergei Skripal, and his daughter Yulia are recovering.

If the deadly poison was, as reported, put on the doorknob of Skripal’s home, how did he and Yulia manage to go to a restaurant after being contaminated, with neither undergoing a seizure until later on a park bench?

If Russia did it, why are the British scientists at Porton Down now admitting that they have not yet determined the source of the poison?

Why would Putin, with the prestige of hosting the World Cup in June on the line, perpetrate an atrocity that might have killed hundreds and caused nations not only to pull out of the games, but to break diplomatic relations with Russia?

U.S. foreign policy elites claim Putin wanted Trump to win the 2016 election. But if Putin indeed wanted to deal with Trump, why abort all such prospects with a poison gas murder of a has-been KGB agent in Britain, America’s foremost ally?

The sole beneficiaries of the gas attacks in Salisbury and Syria appear to be the War Party.

Patrick J. Buchanan is the author of the recent book, Nixon’s White House Wars: The Battles That Made and Broke a President and Divided America Forever.