Here's What You Need to Remember: Additionally, the existence of more S-400s in the region presents additional threat possibilities for Israeli aircraft operating in the region and potentially help fortify paramilitary terrorist groups or other kinds of hybrid-guerilla forces hostile to the U.S. and Israel. 

Russia’s Ambassador to Iran, Levan Jagarian, told an Iranian newspaper that his country may very well sell S-400 air defense systems to Iran, despite U.S. concerns. 

"We are not afraid of U.S. threats and we will live up to our commitments," Jagarian said, according to Iran’s Tasnim News Agency. 

The Trump administration's failure to push to renew the 2015 Joint Comprehensive Plan of Action in 2018 has introduced a new dynamic into the discussion regarding concerns that Iran may sell weapons to some of its proxies. The Trump administration has previously suggested Iranian-supplied weapons would flood into Iraq, Yemen, Lebanon, and other areas where Tehran arms affiliated militant groups, the Iranian paper writes. 

What would it mean for Iran to possess advanced S-400s? The answer, it seems, relies heavily upon the extent to which the Russian-built defenses have been upgraded. The most modern S-400 variants use a new generation of digital processors, computer networking and radar-frequency detection, leading some in the Russian media to claim they are capable of destroying 5th-Gen stealth fighters and B-2 bombers. 

When it comes to legacy or existing Russian air defenses, which Iran has been known to have, the claim that stealth would be extremely vulnerable is, at the very least, highly questionable. Upgraded S-400s, however, and of course S-500s, might present a slightly different scenario. However, that has also yet to be verified. 

Additionally, the existence of more S-400s in the region presents additional threat possibilities for Israeli aircraft operating in the region and potentially help fortify paramilitary terrorist groups or other kinds of hybrid-guerilla forces hostile to the U.S. and Israel. 

The real danger with upgraded S-400s, it would appear, likely pertains to computer processing speeds the extent to which they are networked to one another. If an ability to maintain a “track” on an aircraft improves at higher speeds over greater ranges due to an ability to more quickly integrate and network information than planes could be more vulnerable even if the hardware or munitions themselves have not changed much. For instance, its high-speed data link technology improves the ability for one air-defense location to find and share details with another “node” within a broader system, then broader areas could become vulnerable and the normal radar-evading advantage of flying at high-speeds could be minimized. 

Kris Osborn is the defense editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.

This article was first published in 2020 and is being republished due to reader interest.

Image: Reuters.