NATO opened a high-level meeting on Tuesday against the backdrop of one war in the Middle East overshadowing another on the military alliance’s doorstep. A tentative cease-fire between Israel and Iran is expected to dominate discussions, while Russia’s invasion of Ukraine might muster merely a mention.

But NATO has other things to worry about at its annual summit of alliance leaders in The Hague, the Netherlands — namely, maintaining a unified front amid an internal spat over defense spending.

The new cease-fire, announced by President Trump late Monday, could rally NATO states toward a common goal. It also provides Mr. Trump the opportunity to take a victory lap at the brief gathering, which is designed to avoid diplomatic disruptions over his defense spending demands.

“Counter-intuitively, this could have a positive effect on the NATO summit,” said Liana Fix, a Europe expert at the Council on Foreign Relations.

At the least, Ms. Fix said, the new American role in Israel’s enduring conflict with Iran could distract from “escalation on other issues” at the NATO meeting, which wraps up Wednesday.

Yet exhaustive efforts by Mark Rutte, NATO’s affable secretary general, to keep the summit sweet as well as short are far from assured.