2 Chronicles 28:21 Commentary - English Annotations on the Holy Bible by Matthew Poole

Distressed him, or, straitened him, by robbing him of his treasures. But he helped him not, but strengthened him not; a most emphatical expression: for though he weakened his present enemy the Syrian, as is related, 2Ki 16:9, yet really, and all things considered, he did not strengthen Ahaz and his kingdom, but rather weaken them; for by the removing the Syrian, who, though a troublesome neighbour, was a kind of bulwark to him, as to many other enemies, he smoothed the way for himself, a far more dangerous and mischievous enemy, as appears by his invasion of Judah in the very next king’s reign.