Iran is increasing its military preparations as tensions rise over the possibility of a U.S. ground invasion.

The country is strengthening defenses around key sites, particularly major oil infrastructure, and preparing for a potentially prolonged conflict, according to a Wall Street Journal report.

The Journal report says Iran has been reinforcing missile systems, deploying naval mines along its coastlines, and expanding underground tunnel networks on strategically important islands.

These moves reflect a strategy focused on asymmetric warfare, relying on drones, missiles, and allied militias to counter more advanced conventional forces.

Officials and analysts outside the report have also signaled that Iran is preparing for the possibility of a ground confrontation.

The Guardian reported that Iran's parliament speaker warned the country is "waiting for the arrival of American troops" and would respond forcefully to any incursion.

State-linked messaging has gone further, with rhetoric warning that an invasion could become a "historical hell" for invading forces, according to coverage from Alhurra.

Inside the country, the Journal report describes a broad mobilization effort shaped by memories of the Iran-Iraq War.

Officials are encouraging a culture of "resistance" and calling on civilians to support the military, with even young volunteers being recruited for support roles such as preparing food and manning checkpoints.

Military leaders have also emphasized readiness for escalation.

Reuters reported that Iran's army chief instructed commanders to prepare for any attack with "utmost pessimism and accuracy," underscoring concerns that a ground war could expand quickly if fighting intensifies.

Analysts cited in regional coverage have warned that Iran appears to be bracing for a prolonged and costly conflict rather than a quick engagement.

While Iran's conventional military is less advanced than that of the U.S., the Journal report notes that its terrain and experience with irregular tactics could make any invasion "costly and protracted."

Analysts echoed in Alhurra's reporting suggest Iran's strategy is less about outright victory and more about making a war so expensive that it becomes unsustainable for its adversaries.

Iranian leaders have also warned they could retaliate beyond their borders, potentially targeting regional energy infrastructure and other strategic assets, raising fears that any ground war could quickly expand into a broader Middle East conflict.