IronChariots.org : Chariots of iron
Quotes Bible, namely, most pregnantly:
Joshua 17:18 But the mountain shall be thine; for it is a wood, and thou shalt cut it down: and the outgoings of it shall be thine: for thou shalt drive out the Canaanites, though they have iron chariots, and though they be strong.
Eventually they did. There are no Canaanite communities these days.
Judges 1:19 And the LORD was with Judah; and he drave out the inhabitants of the mountain; but could not drive out the inhabitants of the valley, because they had chariots of iron.
To this they said themselves:
Ray Comfort argued that in the section "he drave out" in Judges 1:19, the "he" refers to the tribe of Tribe of Judah.  This is debatable but it still implies that the tribe could not overcome the chariots even with God's help.
Or because, being afraid, they did not confide in it.
19 And the Lord was with Juda, and he possessed the hill country: but was not able to destroy the inhabitants of the valley, because they had many chariots armed with scythes.
Haydock gives the compilation of comments here:
Ver. 19. Was not able, &c. Through a cowardly fear of their chariots armed with hooks and scythes, and for want of confidence in God. (Challoner) --- Hebrew does not say expressly that Juda could not: quia non ad expellendum, &c. He had not the courage or the will. With God's assistance, what had he to fear? Were these Philistines with their chariots, more terrible than the giants in their fortresses? --- Scythes. Hebrew receb barzel, "chariots of iron." (Calmet) --- The Roman and Alexandrian Septuagint have "Rechab was opposed to them." (Haydock) --- The edition of Basil adds, "and they had chariots of iron," as St. Augustine (q. 5,) reads. A double translation is thus given. (Calmet) --- These chariots were calculated to cut down all that came in contact with them. (Curt. iv.) (Worthington)
Haydock's Catholic Bible Commentary, 1859 edition. JUDGES - Chapter 1