During the visit of Ukrainian President Volodymyr Zelenskyy, U.S. leader Joe Biden announced one particularly important change in U.S. policy. Washington will send Patriot air defense systems to protect Ukraine's skies from Russian UAVs, missiles and air strikes, National Interest wrote.

In a sense, the move also draws attention to Israel. The country has refused to provide Ukraine with the Iron Dome air defense system, with its more than 90 percent probability of intercepting missiles and UAVs. Ukrainian officials actively insist on these systems, with official requests coming from the president's office, the Foreign Ministry, the Defense Ministry and the Ukrainian embassy in Israel.

There are several reasons for Israel's refusal. First, and most importantly, Israel harbors legitimate fears that if any of its systems are deployed, they will be captured by Russia on the battlefield. From there, they are virtually guaranteed to be sent to Iran for analysis. That analysis could allow Iran to find ways to counter those systems on the battlefield... The outgoing Israeli government has made it clear that it is not willing to take that risk. The new government is likely to say the same thing.

Second, Israel is refraining from sending these systems elsewhere when the Israel Defense Forces have already assessed the urgent need to acquire additional systems and interceptors for their own defense. Hezbollah and Hamas weapon arsenals continue to grow despite Israel's largely successful efforts to stop Iranian weapons smuggling. Producing the required number of systems and interceptors will take some time, and the timeline could be pushed back by exports to Ukraine.

Third, the time needed to train Ukrainian forces to operate the Iron Dome will not help Ukraine in the short term. One can understand why Ukraine needs this system, given its success. Nevertheless, the Patriot is likely to be an easier system to train Ukrainian forces.

Finally, Israel does not want to provoke a harsh response from Russia, which maintains a significant presence in Syria, where Israel is regularly active. Recent reports indicate that Russia is withdrawing troops and systems, mostly air defense, from Syria. They cannot maintain Syrian systems due to a shortage of spare parts and refuse to replenish air defense systems destroyed by the Israeli air force.

Biden's decision to send Patriot to Ukraine, of course, carries the same risks. Captured U.S. systems could be used by both Russia and Iran, weakening their effectiveness on the battlefield. It is reported that some American systems have already been seized by the Russians in Ukraine and sent to Iran. But for America, the desire to maintain a U.S.-led world order may trump such fears.

Biden and his advisers must decide for themselves whether such a risk is worth taking. But it is also worth noting that the Pentagon may no longer have enough air defense systems to cover its own deployed forces.