Biden's Air Defense Pledge to Ukraine May Not Be Realistic

President Joe Biden has pledged "to continue providing Ukraine with the support needed to defend itself" in the aftermath of recent Russian attacks, though it remains unknown what that support will look like from a military perspective.

Biden told Ukrainian President Volodymyr Zelensky on Monday, without being specific, that air defense systems would be part of such assistance.

The U.S. in the past has provided High Mobility Artillery Rocket Systems (HIMARS) and stingers, and is slated to send National Advanced Surface-to-Air Missile Systems (NASAMS).

Gabriela Iveliz Rosa Hernández, a research associate at the Arms Control Association, told Newsweek that the U.S. government has pursued a policy based on giving Ukraine the weapons that "are relevant for the current fight."

"Ukraine has long sought air-defense systems to shield itself from Russian missile strikes," Hernandez said. "In theory, Ukraine could use much more advanced systems, such as the Patriot system or the Iron Dome to intercept rockets. The NATO allies could also try to provide more S-300 anti-aircraft systems as they did in the original phases of the conflict because the Ukrainians already know how to use and maintain these systems."

A senior White House official told CNN that the U.S. will continue to help provide Ukraine with short- and long-range air defense systems, again not including specifics.

In August, Biden announced eight new NASAMS as part of a security assistance package. They have not yet been sent—two of the eight are expected to be delivered by November.

Hernandez said there are different variables that influence what kinds of systems the U.S. chooses to provide Ukraine with, adding that the provision of NASAMS falls under a new phase of U.S. security assistance to Ukraine—one which includes smaller systems that are easier to sustain and maintain.

Jordan Cohen, a policy analyst at the Cato Institute, told Newsweek that before they can be provided for Ukrainian aid, NASAMS and other rumored defense systems have to be contracted and built.

"In the arms sales process, most sales usually take years to be delivered, sometimes five or more," Cohen said. "The reason things have been provided so quickly in Ukraine is that much of it has been taken out of existing defense stocks. The two that are expected to be delivered are only two out of the eight. The other six are going to take years to develop, procure and deliver."

NASAMS are currently owned by 12 countries: the U.S., Norway, Finland, Spain, the Netherlands, Oman, Lithuania, Indonesia, Australia, Qatar, Hungary and one undisclosed country.

There are two situations at play in Ukraine, according to John Erath, senior policy director at the Center for Arms Control and Non-Proliferation.

Erath told Newsweek that there's actual conflict on the ground, where HIMARS have proven very effective at hitting key Russian targets. But from a Russian perspective, the country has launched a series of attacks on Ukrainian infrastructure and seems to be playing the long game—focusing on "the larger picture," he said.

"They want to illustrate that the opportunities for gaining more ground are going to get higher as more reservists come in, that the consequences are more severe by making more nuclear threats, and by announcing annexation...they are raising the stakes, should Ukraine capture more territory....The next steps are going to be providing Ukraine with the capabilities to ameliorate, to partially negate, the current set of Russian threats," Erath said.

Cohen said the U.S. and NATO "are in a bind" in deciding what can and should be sent to Ukraine.

Missile defense systems to protect land Ukraine has taken control of would be a good way to stop Russian bombing, he said, though the process is time-intensive.

"The old adage that it is easier to take land than to hold it rings very true right now, especially because of Ukraine's dependence on Western military aid," Cohen said.

Erath said more complex questions remain moving forward, such as if Ukrainians at some juncture decide they've done enough and have regained enough of their territory to get a ceasefire.

Or, Russia could hold on and continue to build its forces and attack after the winter.

"At this point, Ukrainian resolve has been very high," he said. "I would suspect that they would want to continue this as long as they can....We have to remember we are talking about people's lives here. The more the war goes on, more people are going to die."

Newsweek reached out to the White House for comment.