The Trump Administration is mulling an order designed to designate the Muslim Brotherhood as a foreign terrorist organization. The best approach would be a piecemeal one: Some Brotherhood branches belong on that list, some don’t — and making the distinction will help President Trump more effectively fight the war on terror.

It’s no secret why the Muslim Brotherhood is in the crosshairs. Its hateful and anti-Western worldview has long served as an ideological gateway to jihadi terrorist groups. Famously, Osama bin Laden’s partner in founding al Qaeda was a Muslim Brother named Abdullah Azzam. And while al Qaeda has broken with the Muslim Brotherhood on a range of political issues, Brotherhood thinkers have undeniably shaped al Qaeda’s ideology over the years — and the ideology of other jihadist groups, too.

The Brotherhood has evolved quite a bit since its founding in Egypt in 1928. For one, the group now operates worldwide. Over time, the political and military pressure from host governments in the Middle East also forced the Brotherhood to dial back on its overt extremist positions. Under the threat of annihilation, these groups had little choice to but to lay down their weapons and embrace politics.

By the time officials in the George W. Bush administration considered making a case against designating the Brotherhood, the picture had become blurry. It appeared that many of the disparate groups comprising the global Muslim Brotherhood had soured on the strategic value of prioritizing violence. Of course, this didn’t mean the movement no longer held extremist views. It had simply become difficult to definitively prove that its component parts formed a global terrorist organization.

If anything, there were some branches of the Brotherhood that seemed to meet criteria, while others were a heavier analytical lift. More than a decade later, this is likely still the case. The Brotherhood in Libya, Syria and Yemen (the Islah Party) have apparent ties to jihadis. The Muslim Brotherhood in Jordan (Islamic Action Front), which has marketed itself as a political entity, may be more difficult to designate.

In the end, the intelligence will either meet the legal criteria, or it won’t. There’s no fudging it. Of course, we can augment our own intelligence with help from allied countries. We can ask for help from Arab countries like Saudi Arabia and Bahrain, which designated the Brotherhood as a terror group.

Jordan and Egypt may also be willing to share intelligence about their local chapters, which have long sought to challenge the regimes. But Washington must vet that intelligence very carefully. These states have a longstanding desire to weaken their Islamist opposition at all costs.

Once some Brotherhood branches are designated, it may become easier to target others. When certain branches or even leaders of the Brotherhood are caught providing financial, technical or material support to listed entities, they immediately become candidates for designation.

Meanwhile, there will be opportunities to take further action at home. According to an official Treasury report submitted in December, “The US has not designated a domestic US-based charity since . . . 2009.” In other words, it appears that the Obama administration placed an unknown number of terrorist financing cases on hold at the Department of Justice over the last eight years.

Trump should instruct the DOJ to reopen them. When these cases meet criteria, they should be prosecuted. And if they involve Muslim Brotherhood activists, that nexus should be made clear.

Finally, the Trump administration has one last crucial point of leverage to undermine the financing of the Muslim Brotherhood. Qatar and Turkey, two countries typically viewed as US allies, are the top financial and logistical supporters of the Brotherhood worldwide. They also serve as financiers and headquarters to the Brotherhood’s most violent branch: Hamas.

The administration should call upon Qatar and Turkey to end support for Hamas. They should also be warned about their support for Brotherhood branches that appear to be engaged in violent activity or even simply spreading extremist rhetoric.

The administration has a number of options at its disposal shy of a blanket terrorist designation. Because going after the “mother ship” may not ultimately hold up under legal scrutiny, an incremental approach may have a higher likelihood of success. That may also ultimately lead to a broader campaign against the Muslim Brotherhood that enjoys the backing of foreign partners and American skeptics alike.

Jonathan Schanzer, a former terrorism finance analyst at the US Department of the Treasury, is senior vice president at Foundation for Defense of Democracies.