Leslie Vinjamuri is an associate fellow at Chatham House , where she serves on the US and the Americas program as well as on the institute's council. She is also associate professor in international relations at SOAS University of London . The opinions in this article are those of the author.

The honeymoon period will be officially over, and Trump will post the lowest approval rating -- 44%, according to a CNN/ORC poll -- of any newly elected president since modern polling began.

The biggest surprise for many at the end of these first 100 days will be the degree to which the Trump presidency has been normalized.

For some, this is justified by the fact that few US policies have changed as radically as feared and international institutions remain intact.

Trump's "America First" agenda has not produced radical change in the nation's formal international commitments, and few of his more incendiary campaign promises have materialized.

Trump pledged to play hardball with America's friends and foes (but not Russia) and to eliminate NAFTA, at least in its current form.

Instead, he has (if unwittingly) taken a harder line on Russia and affirmed America's commitment to NATO . He has backed off his pledge to label China a currency manipulator and reaffirmed America's commitment to a "One China" policy, preferring to work with China to counter the threat presented by North Korea's nuclear program.

And he has recognized the importance of Japan and South Korea, key US allies in northeast Asia. Despite his contempt for multilateral trade deals, he has yet to renegotiate the North American Free Trade Agreement, but he says he will

But there is still much at stake. The erosion of core international norms, programs and diplomatic practices is underway. In a mere three months, the President has managed to cast a shadow over the United States, raising grave doubts as to whether America is any longer fit to lead the free world.

Formal commitments might look more or less the same -- at least for now -- but anyone who thinks that Trump's flaws are a matter of style and that they carry no consequence is likely to be disappointed.

The Trump presidency seems hopeful that moral authority can be sustained on the back of hard power alone. Trump's budget proposal seeks to increase military spending and cut (drastically) programs and networks that sustain America's leverage through the exercise of moral authority and soft power. Investments in long-term foreign assistance and international diplomacy are being given short shrift.

JUST WATCHED Where Trump's campaign promises stand Replay More Videos ... MUST WATCH Where Trump's campaign promises stand 03:20

Trump relied exclusively on hard power to respond to Assad's use of chemical weapons. The strikes on Syria's airfield were Trump's boldest statement on behalf of international morality. This has so far proved to be his most popular foreign policy. The missile strikes were supported by a majority of Americans. They also contained the element of surprise. Few would have thought that the President's first spectacular use of hard power would be aimed at enforcing an international humanitarian norm.

But hard power is costly. It carries risks. And it leaves most jobs undone. Syrian President Bashar al-Assad may or may not comply with the Chemical Weapons Convention, and his attacks on civilians continue as does war in Syria.

Assad's chemical attacks have driven a wedge between Russia and the United States, making it even harder to craft a political solution to the conflict. Abandoning the instruments of soft power is an exercise in futility for a President who seeks to reduce America's commitments while maintaining its leverage.

Exercising moral authority and soft power effectively will require Trump to think carefully about the words he chooses. This will be a tall order, but the proof is in the pudding and Trump is collecting a lot of evidence to suggest his words really do matter.

In the aftermath of the Turkish referendum, which has allowed Recep Tayyip Erdogan to tighten the screws even further on Turkey's democracy, Trump rushed to congratulate Erdogan on his success. When monitors from the Organization for Security and Cooperation in Europe declared the referendum to be deeply flawed , Trump did not waiver or reassess his views.

Only days later, what may have seemed to Trump as an exercise in cheap talk has proved to be costly. On Tuesday, Turkey launched an attack against Kurdish US-backed anti-ISIS forces in northern Syria . Trump's congratulatory phone call did little to tame Turkey's President. It may even have encouraged him. Either way, Erdogan saw no need to give the US President advance warning of his intended military action.

When it comes to moral leadership though, few are lining up to take over from the United States.

When Assad launched his chemical attacks, there were no other contenders set to respond. Instead, British Foreign Secretary Boris Johnson supported the American strikes, then canceled his trip to Moscow and decided to stay home, leaving it to US Secretary of State Rex Tillerson to manage tensions with Russia.

Some have touted German Chancellor Angela Merkel as a possible replacement. At Davos, President Xi Jinping positioned China as the lead proponent of globalization. Others may be skeptical. And recently, Japan set out to revive the Trans-Pacific Partnership, even if doing so means leaving the United States behind.

But none of these alternatives offer the same combination and promise of principled leadership, collaboration and hard power that the world has grown to expect, even if a degree of hypocrisy has been a necessary part of the ride.