When Ukrainian President Volodymyr Zelenskyy told the world last month, “I need ammunition, not a ride,” the ammo he especially wanted was anti-tank and anti-aircraft missiles. Since then, countries around the world have energetically responded, sending shipments that include Javelin anti-tank missiles and Strela anti-aircraft missiles.

Brock University Associate Professor of Operations Research Michael Armstrong says Zelenskyy’s request, and the international response, reflect how these missiles are particularly effective for defensive fighting and “asymmetric” warfare.

“The missiles are primarily defensive because the technology works best when used by stationary infantry against targets moving nearby,” says Armstrong, a faculty member with Brock’s Goodman School of Business whose research has examined naval missile warfare and Israel’s Iron Dome rocket interceptor systems.

He says some of the smaller versions resemble Second World War bazookas. Soldiers might fire the anti-tank missiles at vehicles driving past them along a road, and the anti-aircraft missiles at jet fighters flying overhead.

Armstrong says this feature makes it more politically acceptable for governments to send the weapons to Ukraine, which is receiving shipments from NATO members such as Canada, Germany and the U.S., as well as traditionally neutral countries such as Sweden.

“These small missiles are also well-suited to asymmetric situations, where one side is much weaker than their opponent,” he says. “They are relatively cheap but can destroy tanks and aircraft costing millions of dollars more.”

This allows Ukraine to counter Russia’s large military hardware advantage and make the odds slightly less uneven. Reports suggest Ukraine is using the weapons very effectively.

A ‘Saint Javelin of the Ukraine’ image has become an international meme with the images showing a woman dressed in medieval Orthodox robes, but carrying a Javelin anti-tank weapon.

Ironically, Russia’s predecessor state, the Soviet Union, was a pioneer in developing both missile types. For example, Egypt used Soviet-supplied missiles to inflict heavy losses on Israeli tanks and aircraft during their 1973 war.

However, the missiles have limitations, Armstrong says. They can help slow down Russian forces advancing toward Ukrainian cities like Kyiv, but they’re less effective at pushing the Russians out once they’ve surrounded cities like Kharkiv. Tanks and warplanes are more useful for that mission. So, even with the missiles, the odds against Ukraine look formidable.