The latest outbreak of conflict is only days old, but some longer-term challenges for the West are apparent.

Hamas’ unprecedented attack on Israel combined terrorist tactics with irregular warfare and information operations. This ongoing hybrid conflict could easily escalate to involve Hezbollah in Lebanon and its benefactors in Iran. Israel’s response will shape the evolution of the crisis and the geostrategic consequences. While much about the attack’s planning, its backers, and intelligence failures remains unknown, some transatlantic implications are already clear.

First, terrorism is back on the security agenda. There is a long history of episodic attention to terrorist risks and counterterrorism strategies. The scale and brazen nature of Hamas’ attack, which involves North American and European victims and hostages, will elevate terrorism as a concern for publics and policymakers on both sides of the Atlantic. There is also the potential for individual jihadi attacks on Western targets inspired by events in Gaza.

Second, an effective response, whether diplomatic or military, to Iran’s nuclear ambitions has become essential. The outbreak of conflict in the Middle East, including skirmishes between Israel and Hezbollah, dramatically underscores the risks of Iran’s becoming a nuclear-armed state. If the country’s regional clients are willing to launch attacks of such devastating scale today, how much more aggressive would they be under an Iranian nuclear umbrella? The Biden administration has attempted to restart nuclear diplomacy with Iran, something widely supported in Europe, while restraining Israeli action. Current circumstances mean few on either side of the Atlantic will be willing to tolerate the prospect of an Iran with access to nuclear weapons. The odds of a preemptive strike against Iran’s nuclear facilities have shortened considerably.

Third, NATO and the EU will be compelled to give higher priority to counterterrorism, spillovers of political violence, and other risks emanating from Europe’s southern periphery. Recent summits and strategy documents have noted these challenges, but they have taken an understandable back seat to the war in Ukraine and competition with China. The transatlantic partners will now need to reconcile these competing demands. How they will do so is unclear, but it is a critical issue given Ukraine’s continuing defense needs and the standing potential for direct NATO confrontation with Russia.