Foreign policy moments that mattered in Trump's first 100 days Decisions about life and death, war and peace, military and diplomacy.

 -- Just shy of his 100th day in office, President Donald Trump — the first U.S. president with no political, military or foreign policy experience — has shaken up the globe, surprising allies with his demands, adversaries with his military action and maybe even himself with his new power.

“I never realized how big it was,” he told The Associated Press in an interview Friday. “I really just see the bigness of it all but also the responsibility. And the human responsibility. You know, the human life that’s involved in some of the decisions.”

During his short time in office, Trump has had to make decisions about life and death, war and peace and military and diplomacy as his administration exerts itself on the world stage. Here are the top foreign policy moments of his first 100 days.

Surprise strikes on Syria

The “America first” president shocked the world with his muscular response to the use of chemical weapons in Syria. Just days after the Syrian regime of Bashar al-Assad reportedly attacked the town of Khan Sheikhoun with sarin gas, Trump ordered 59 Tomahawk strikes on the air base where Assad’s planes are said to have taken off.

“I now have responsibility, and I will have that responsibility and carry it very proudly,” he said at a Rose Garden press conference with Jordan’s King Abdullah.

Critics on the left and right were surprised that the businessman who had decried years of wasteful spending on wars in Iraq and Afghanistan was ready to play the world’s policeman. But allies, from the U.K. to Israel, applauded the response, even as Russia and Iran blasted the U.S. for the attack on their ally Assad.

The administration has left the door open to more strikes against Assad for further violations of international laws and norms, although it has faced some confusion on its views of Assad’s future and its priorities in Syria.

High-stakes diplomacy with China

If Syria was a moment of crisis for Trump, China has been the steady challenge.

Candidate Trump bashed China constantly, citing the country as a source of America’s problems, often with graphic language. It was manipulating its currency, stealing American jobs, beating the U.S. on trade, even raping the American economy.

But now that he’s in office, Trump has taken a more nuanced tone, culminating in a two-day summit at his private club Mar-a-Lago with Chinese President Xi Jinping. Trump agreed to abide by the U.S.’s long-standing one-China policy, not to label China a currency manipulator and, so far, not to slap it with the sort of tariffs that critics said would start a trade war.

Instead, Trump appears to be using that tough economic talk as leverage to get China to help with North Korea. Since the summit, Trump and Xi have spoken twice by phone, and China may be pressuring its ally and neighbor North Korea a bit more.

This is an important space to watch, though, as the stakes in North Korea rise or if domestic politics in China changes.

Boiling tensions with North Korea

Key to that is what happens next in North Korea, where every day the rhetoric seems to heat up. North Korea has been pursuing a nuclear missile capable of reaching the continental United States for years, and it just could happen under Trump’s watch.

On a critical trip to Japan, South Korea and China, Secretary of State Rex Tillerson said that all options are on the table and that the time for “strategic patience” is over. And Trump said the U.S. would send a strike group and a nuclear submarine to the area, although it took some time before the USS Carl Vinson and company actually headed toward those waters.

Now the world anxiously awaits what that means if North Korea successfully tests an intercontinental ballistic missile or another nuclear bomb. If Trump strikes pre-emptively, will it mean all-out war on the Korean Peninsula, as strongman Kim Jong Un has promised?

So far, the administration is pursuing diplomatic and economic options in the face of those fiery words and the detention of a third American citizen by the Kim regime. The pressure on China to do more is working, the White House says, and this week Trump and Tillerson will address the United Nations Security Council to push for full implementation of existing U.N. sanctions.

But even then, it’s unclear how far China is willing to go on North Korea, since it fears destabilizing or toppling the regime. Trump and Kim’s next moves are treading a fine line here as the world holds its breath.

The Russian question

For months now, the Trump administration has been dogged by questions about ties between his advisers and the Russian government. Those questions still loom, as the FBI and two congressional committees investigate.

It has created a dilemma for Trump, who promised to “get along” with Russia and work on what he saw as common issues, including terrorism. Complicating that campaign promise are the politics of working with the country, which reportedly hacked his election opponent to favor him, and the situation on the ground in places like Syria, where Russian President Vladimir Putin has labeled as terrorists and even targeted American-backed rebels.

That tension came to a head with Tillerson’s big visit to Moscow earlier this month, meeting with Putin and Foreign Minister Sergey Lavrov. The trip, announced at the same time that the State Department initially said Tillerson would skip a NATO foreign ministers’ meeting, was pounced on by critics, who said the Trump administration was insulting European allies in favor of Russia.

In Moscow, Tillerson and Lavrov commented that U.S.-Russian relations were at a low point. They tried to paper over major differences on Syria and promised to take steps to work together — although no tangible changes have been announced so far.

Accelerating the fight against terrorism

The most apparent change in U.S. foreign policy may be what Trump has done to the military, pushing for a more robust, muscular presence to take on terrorist groups around the world.

The administration granted new capabilities to commanders in Yemen and Somalia, allowing them to conduct more airstrikes without individual White House approval. It returned strike authority to battlefield commanders in Iraq and Syria. And the military dropped one of the world’s largest nonnuclear bombs on an ISIS cave complex in Afghanistan.

But the increased activity has created more risks too. Early in his administration, a controversial raid in Yemen killed several civilians and a U.S. Navy SEAL. U.S. airstrikes in Mosul, Iraq, and Jinnah, Syria, may have killed hundreds of civilians. The military is still investigating those claims, but it revealed that it mistakenly bombed a U.S.-backed Syrian rebel position, killing 18 allied fighters.

In its fight against terrorism, the Trump administration has also targeted what it sees as the world’s leading sponsor of terrorism, Iran. While it reviews its Iran policy writ large, especially whether it will abide by the nuclear agreement, it has blasted Iran for its support for terrorists in Syria, Yemen and Iraq; for harassing U.S. ships in international waters in the Persian Gulf; and for its missile tests and continued pursuit of a nuclear bomb, according to Tillerson. That review should conclude in mid-July.