It is likely that many of those will proliferate outside of the Ukraine and some of those weapons will inevitably hit those who now deliver them.

In a review of the U.S. war on Syria Aaron Maté details how the Obama/Biden team empowered terrorist networks in Syria:

Based on declassified documents, news reports, and scattered admissions of U.S. officials, this overlooked history of how the Obama-Biden team's effort to oust the Assad regime – in concert with allies including Saudi Arabia, Qatar, and Turkey – details the series of discrete decisions that ultimately led the U.S. to empower terror networks bent on its destruction.

The U.S. pushed an enormous amount of weapons into Syria. Those weapons did not end up with the 'moderate rebels' the U.S. propaganda had elevated but in the hands the most ideological committed and most brutal actors on the ground:

Although the Obama administration claimed that the weapons funneled to Syria were intended for "moderate rebels," they ultimately ended up in the hands of a jihadi-dominated insurgency. Just one month after the Benghazi attack, the New York Times reported that "hard-line Islamic jihadists," including groups "with ties or affiliations with Al Qaeda," have received "the lion's share of the arms shipped to the Syrian opposition.