Among the security benefits Iran receives from its ties to non-state actors are deterrence, intelligence sharing, assistance with counterintelligence operations, counterterrorism, and power projection.

The president's tweets suggest he barely understands the country he's repeatedly demonized. This is troublesome given how much influence he has on what happens next.

The best way to address the various challenges associated with Iranian behavior—meaning the one most likely to succeed and to bolster long-term U.S. security interests—is to preserve and build on the nuclear deal. Doing so would enable Iran to reconsider the lessons of the Iran-Iraq War, which taught it that it cannot trust the international organizations and world powers that seek to isolate it and undermine its security.

"The current nuclear agreement with Iran may not be perfect—no such deal ever is. But instead of scrapping an imperfect deal and pushing for regime change in the unlikely hope it will fundamentally change Tehran's behavior, U.S. policymakers should learn from history. Regime change is a destabilizing process with an uncertain outcome. Washington should instead focus on how best to limit the country's technical capabilities—which the nuclear agreement has restrained."

Recent incidents put the Iranian drone program on Western observers' radar as a new potential threat associated with the Islamic Republic. But Iran's drone program actually started decades ago and serves a number of military and civil purposes. As Tehran deploys its drones more regularly, for more purposes and in more locations, policy-makers will have understand the program's nature, scope, strengths, and limitations, if they want to effectively respond to it.

"By building on the nuclear deal, as the European Union has done since it was reached in July 2015, the international community can undermine Iran's hardliners who see self-reliance as the only way forward and the IRGC as central to the pursuit of self-sufficiency. Preserving the JCPOA can also help empower the moderates, who, backed by the Iranian public, wish for more international integration, including economic interdependence and political engagement. Key decision-makers in Iran understand that none of this will materialize without deep-reaching reform. In fact, the moderate President Hassan Rouhani has made curbing the IRGC's reach a top priority."

"With tensions high, small missteps can turn into serious crises, which could further destabilize the already fragile country. To avoid such an outcome, it’s more necessary than ever for the United States to understand what’s driving Iran’s Afghanistan policies. This can ensure a sustainable peace in Afghanistan as the United States considers the future of its presence there. To help manage tensions, the United States should at a minimum contemplate reestablishing a channel of communication with Iran—preferably one that avoids high-profile meetings and ensures some level of continuity—similar to the one created during the Obama administration."

"The United States and Iran are the two key players in the fight against ISIS, not least of all because they are two of the group's main targets. Indeed, other countries, particularly in Europe, have also been targeted by the group and seen ISIS attempt to recruit among their populations. As a result, they also share an interest in combatting the group. But the United States and Iran have made the fight against ISIS a security policy priority and allocated considerable resources to undertaking efforts in Iraq and Syria. While the two adversaries have aligned interests in Iraq, they have undertaken separate counterterrorism efforts to tackle the group."

"If Iraq's Kurds succeed in creating and sustaining a functioning state, Iran will certainly be deeply affected. First, a successful independence movement in Iraq would almost certainly revitalize similar Kurdish efforts in Iran. And that, in turn, could lead other minorities to push for independence....The ease of movement, shared language, and common media outlets between the Iraqi and Iranian Kurdish populations will make political spillover likely."