Will the US and Iran be primary actors on opposite sides of a war before 2025?

On October 7, 2023, Hamas launched a surprise attack on Israel. Some reports have suggested that Iran was closely involved in planning the attack. The Wall Street Journal reported:

Iranian security officials helped plan Hamas’s Saturday surprise attack on Israel and gave the green light for the assault at a meeting in Beirut last Monday, according to senior members of Hamas and Hezbollah, another Iran-backed militant group.

Officers of Iran’s Islamic Revolutionary Guard Corps had worked with Hamas since August to devise the air, land and sea incursions—the most significant breach of Israel’s borders since the 1973 Yom Kippur War—those people said.

However, Iran has denied that it was involved and US Secretary of State Anthony Blinken has stated:

In this specific instance, we have not yet seen evidence that Iran directed or was behind this particular attack. That’s something we’re looking at very carefully, and we’ve got to see where the facts lead.

Tensions between the US and Iran have been high in recent years following the US withdrawal from the Iran nuclear deal in 2017, the US assassination of Iranian general Qasem Soleimani in 2020, and Iran's enrichment of uranium to levels approaching those needed to create a nuclear weapon. Some observers have expressed fears of war between the two countries.

The Uppsala Conflict Data Program (UCDP) has been collecting data on organized violence for nearly 40 years. The UCDP tracks and categorizes conflicts and conflict deaths according to a specific set of definitions. The following sample of conflicts involving the US illustrate some of the different categorizations (note that these categorizations may not necessarily correspond to those specified in the resolution criteria):

• The 2003 Iraq war involved Australia, the UK, and the US as primary parties on one side of the conflict, with Iraq as the primary party on the other side.
• In the conflict between Yugoslavia and Kosovo the NATO member countries, including the US, are listed individually in 1999 as secondary warring parties reflecting NATO's bombing of Yugoslavia.
• In the conflict between Iran and Israel the United States is listed as a secondary warring party starting in 2020 when the US assassinated Soleimani and Iran's retaliatory attack against US military bases in Iraq.