As protests engulf parts of Northern Ireland, why is Joe Biden travelling there?

U.S. President Joe Biden‘s visit to Northern Ireland coincides with a particularly delicate time in politics there.

Dissidents in the city of Londonderry have been attacking police just a day before Biden‘s arrival. Most of this occurred during a rally opposing the 25th anniversary of the peace accord that capped the decades of sectarian violence known as the Troubles.

So what’s behind Biden‘s visit, and why does it matter?

Biden, along with the British Prime Minister Rishi Sunak, are marking the anniversary of that peace accord. Known as the 1998 Good Friday Agreement is was supported at the time by former President Bill Clinton. The fellow Democrat played a hand in its negotiations.

Biden has Irish ancestry, often quotes Irish poets, and is the first American president to visit Northern Ireland in 10 years.

But the trip comes at a sensitive political time. For example, pro-British unionists loyal to London continue to boycott the power sharing government. This was a major part of the Good Friday Agreement.

And because of Brexit, one of Belfast’s political parties, the Democratic Unionist Party, or DUP, is also protesting trade rules. These rules treat Northern Ireland different from the rest of the UK.

On Biden‘s agenda are meetings with representatives of five political parties, and he’s expected to float American investment opportunities to help break the impasse, but the White house said he was not planning to pressure them.

The DUP has previously criticised Biden when he waded into that Brexit debate before.

Violence also still crops up sporadically here.

The British intelligence agency MI5 recently raised the threat level for domestic terrorism in Northern Ireland to “severe,” the highest since the rating system was introduced 13 years ago.