Tuesday is Donald Trump's last day in office.
His unpredictability and America First policy have shaken the post-WWII global order and strained relations between Western allies.
As the 45th president of the US vacates the White House, we take a look at the main ways his four years in office have impacted the Old Continent.
In America we trust?
During his presidency, Trump publicly snubbed or berated European allies — seemingly refusing to shake Angela Merkel's hand at the White House — but cosied up to long-time foes — he described Vladimir Putin as a "terrific person" and Kim Jong-Un as a "great leader".
He also pulled out or threatened to pull out of international treaties or institutions promoting a rules-based global order. Washington withdrew from the Paris Agreement on climate change and from the landmark nuclear deal with Iran and initiated the process to pull out of the World Health Organisation (WHO) in the midst of a global pandemic. Trump also fustigated the World Trade Organisation (WTO) and NATO.
For Ian Bond, director of foreign policy at the Centre for European Reform (CER) think tank, "the biggest impact" of Trump's presidency for Europe, was "the loss of trust in America's reliability as an ally."
"There had been serious transatlantic disagreements in the past — notably over Iraq in 2003 — but no previous president since World War II had challenged the very principle of the transatlantic alliance in the way that Trump did when he questioned whether the US ould feel obliged to defend a NATO ally that was attacked," Bond told Euronews.
A survey released on Tuesday of 15,000 people from 11 European countries found that a majority — 51 per cent — believe that the incoming Biden administration will be unable to repair the country's internal divisions and won't invest in solving international issues such as climate change, peace in the Middle East, relations with China, and European security.
Furthermore, just 10 per cent of the respondents described Washington as a "reliable" security partner who will always protect Europe. At least 60 per cent of those surveyed in every country polled also feel that their country cannot depend on US support in the event of a major crisis.
Over the past four years, Europe has had to wrestle with past and new crises — financial, economic, migratory and sanitary. These have exposed stark ideological differences in Europe and strained relations between member states.
European leaders propelled to power on a populist message found an ally in Trump.
"We've seen the Trump presidency embolden leaders such as Viktor Orban in Hungary or PiS (the ruling Law and Justice Party) in Poland because they were able to have good ties with the US without having to contend with particular US interest on some of the democratic norms," Kristine Berzina, a senior fellow at the German Marshall Fund of the United States, told Euronews.
"At the same time that has played into European conflict and so an area in which Europe is weaker is perhaps its cohesion," she added.
Charles Kupchan, a senior fellow at the Council of Foreign Relations (CFR) concurred.
"Trump strengthened illiberal political forces in Europe," he said. "The result was deeper internal divisions within the EU, as we saw during the recent efforts of Warsaw and Budapest to hamper passage of the EU budget."
Defence and foreign policy
Unpredictability from Washington, including the abrupt decisions to pull US troops deployed in Europe or supporting allied Kurdish fighters in Syria, as well as Trump's repeated criticism of low defense spending from European NATO allies prompted the EU to vow to be "more assertive" on the world stage.
This is generally seen as a good thing, even across the pond.
"The stronger Europe becomes geopolitically, the better partner it will for the United States. More Europe would strengthen, not weaken, transatlantic relations," Kupchan told Euronews.
But whether Europe can walk the walk alone remains to be seen.
"On foreign policy, it's hard to see that the EU was more active during the Trump era than before," Bond argued.
"Although it found ways to avoid the worst effects of his disruption, the EU operating in this environment on its own was a lot weaker than the EU operating alongside the US to support the rules-based order.
"The EU's neighbourhood, from Libya to Belarus, is riven by conflicts that in most cases the EU has not even tried to solve. Europe needs to get serious about defense and security Biden is more Atlanticist than Trump but there is no guarantee that Biden's successor will be, and Europe needs to be able to do more for itself," he went on.
Additionally, a more assertive Europe could splinter the alliance. Relations with China offer a prime example, Berzina said.
Sino-Amerian relations "soured very quickly" during Trump's years in office resulting in a trade war, while the EU-China relationship is "more nuanced," with Brussels describing Beijing as a "systemic rival" and then signing an investment deal, she flagged.
The bloc's approach, she continued, raises the question of "whether Europe's new trade deal with China is an example of European autonomy and European strength — the ability to get an agreement through — or is it an example of China achieving its aim of separating Europe and the US as a strategic bloc?"
Climate change and digital rights
Europe's growing global ambitions extend past defence and foreign affairs as Trump's pull-back on issues including climate change has provided Europe with an opening to step in and take leadership.
The Biden administration is unlikely to find fault with that.
But Europe's aspiration to be the world's standard-bearer on other issues, especially digital protection and taxation, might not be quite as welcomed stateside, particularly given they primarily target large US companies.
"Because Europe has been very assertive and ambitious on these issues in the late Trump years, it's going to be more difficult to find a common position with the US once the new Biden administration comes in and so it is possible for these areas of potential cooperation to instead become areas of contention," Berzina highlighted.
But despite the challenges facing the transatlantic relation brought forward by the Trump administration, his departure from the White House should see Western heads of state breathe a sigh of relief, experts say.
"It has been a long and painful four years. Time to heal and move forward," Kupchan concluded.