A near-term conflict in the Middle East is likely.
The first concern is the increasingly overt hostility between Saudi Arabia and Iran. While both nations have long despised each other, the rising power of Saudi crown prince Mohammed bin Salman, and the post-nuclear deal confidence of Iranian hardliners under the Islamic Revolutionary Guard Corps have exacerbated tensions.
In the past fortnight, we've seen a ballistic missile launch by IRCG-supported Houthi rebels in Yemen against the Saudi capital, Riyadh, and in the (likely Saudi-encouraged) resignation of Lebanese Prime Minister, Saad Hariri. Led by the Saudis, we've also seen a number of Sunni Arab nations calling on their citizens to leave Lebanon.
So what's going on?
Well, Saudi Arabia has described the missile attack as an "act of war" and U.S. officials say the missile is Iranian in origin. This suggests an IRGC test of Salman's response: The IRGC would not have risked killing hundreds of Saudi civilians unless they felt prepared to deal with any retaliation. Still, the Iranians know Salman is determined to alter the strategic balance of power at home and abroad and they want to understand his resolve.
Similarly, on the Lebanese front, while tensions have steadily grown since last November, Hariri's resignation suggests that opportunities for compromise are plummeting.
Indeed, considering the missile attack and the situation in Beirut, it is feasible that Salman might now order a Saudi military strike on Hezbollah in Lebanon. Hezbollah targets in Lebanon are only about 200 miles from Saudi soil and Salman wants to appear strong. The challenge is that Hezbollah and Iran would almost certainly respond to such a strike.
Of course, Iran may also attempt another provocation. Even if neither side favors escalation, both nations view each other through an existential lens of paranoia, so the consequences for miscalculation and uncontrolled escalation are vast.
Nevertheless, this crisis isn't just about Saudi Arabia and Iran.
There's also Israel's desire to prevent Iran from establishing a contiguous ground supply line between Iran and Lebanon's southern border with Israel. The Israelis rightly fear that Iran will employ this logistics network to establish a long-term military presence in Syria; via which men, missiles and materiel can quickly be pushed to Hezbollah forces in Lebanon.
Speaking recently, Israeli Prime Minister Benjamin Netanyahu pledged he would not allow Iran to establish a sustained air force or naval garrison presence in Syria. But if Iran keeps trying to do so, recent history suggests that Israel may well take military action.