The Trump administration has had a rocky start. There was the defeat on Obamacare, staffing the departments has been far too slow, the National Security Advisor lasted only three weeks, there has clearly been infighting in the White House staff, and there have certainly been too many tweets.

But that 75-day break-in period has just ended, and the Trump administration can truly be said to have started only now. The president has been chief executive since January 20, but this week he acted also as Commander in Chief. And more: He finally accepted the role of Leader of the Free World.

This was unexpected: He had appeared to say, during the campaign, that this kind of global leadership role was just too expensive. We were tired of it, tired of having others take advantage of us. We could not solve all the world's problems.

But the strike at Syria had at its heart precisely that kind of global leadership, to enforce the century-old ban on chemical warfare—in the interest of decency and peace. His remarks ended with words that many predecessors, from Wilson to Roosevelt, and Kennedy to Reagan, might have spoken: "as long as America stands for justice then peace and harmony will prevail."

Explaining the strike, Secretary of State Tillerson pointed to one clear security goal: "if there are weapons of this nature available in Syria, the ability to secure those weapons and not have them fall into the hands of those who would bring those weapons to our shores to harm American citizens." But then he added "it's important that some action be taken on behalf of the international community to make clear that the use of chemical weapons continues to be a violation of international norms." The term "on behalf of the international community" is certainly not one we have previously heard from the Trump administration.

This strike will save lives—in Syria, by preventing Assad from daring to use chemical weapons again, and in unknown future conflicts where the losing side will be tempted to employ chemical weapons, and will think twice and not do it. Trump saved more lives in Syria by his action this week than Obama did in all his years in office.

And the strike will have far wider effects. It was undertaken while Chinese president Xi was with Trump in Florida. Surely this new image of a president willing to act will affect their conversations about North Korea. Vladimir Putin will think again about his relations with the United States, and will realize that the Obama years of passivity are truly over. Allies and friends will be cheered, while enemies will realize times have changed. When next the Iranians consider swarming around an American ship in the Gulf, they may think again.

Of course this was an easy lift militarily: a few dozen missiles, one air base as a target. Yet our previous president refused to do it; this one acted. He did not let worries about the possible Russian reaction scare him off. He understood that this would not end the war in Syria, but he did it anyway. He was willing to act alone, without demanding a UN Security Council meeting or congressional vote. And of course, leadership pays off: he will have strong bipartisan support on the Hill.

Henceforth when he speaks of American conditions and demands, interests and desires, more attention will be paid. Every official in every foreign government has been trying to figure him out since November 8. This week he gave them a lot to think about. He took command, and issued orders. He didn't draw a red line and then withdraw it, but instead called Assad's action intolerable—that overused word—and then proceeded to show that when he said intolerable, he meant it.

Trump's decision may create an opportunity for negotiations over Syria. The talks have never been serious because one can never achieve at a conference table what he has failed to achieve on the battlefield. But the battlefield may look a bit different now; it may be worth a try. Trump is right in saying that there were earlier opportunities in Syria and he inherited a mess, but perhaps some kind of real a cease-fire or truce is attainable this year. He has certainly boosted the chances.

The president has obviously not solved the problem of war in Syria, or that of ISIS, or Al Qaeda, or a rising China and an aggressive Iran and a hostile Russia. Of course not. Moreover, he may waver in the coming months, and lead analysts to wonder if the Syria strike was a one-time emotional response to the sarin gas attack.

But he has put us back on the map in a new way; he has created some new space. Consider the alternative: Syria uses sarin and kills babies, defying us and laughing at the unanimous Security Council decisions and its own pledges—and we do nothing. That's a far worse situation for the United States. When the president said it was in the "vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons," he was right. It is also in our vital national security interest to stand for justice, and peace, and liberty, and it appears he is coming to see that. That's the most encouraging thing of all.