At what? Volleyball? Tiddlywinks? Offence? Defense? I would rate them number one or two at defense. The US obviously couldn't stop a significant attack on our soil. I would rate the US number 3 or 4 at homeland defense. You need to compare apples to apples.
Israel is not an offensive (expeditionary) force, as is the US.
Force ratios between the IDF and PLA? LOL! (Israel has nukes. That would be a force multiplier, even if never used.) In what context? Your question indicates your lack of understanding.
/john
PLA's army is clearly huge. You underestimate the strength in numbers. While force multipliers are helpful, having a 1000:1 ratio is not. IDF does not have tactical nukes. Most sources report that the nuclear devices are fighter based or missile warheads in the 20Kt range.
Regarding your characterization of homeland defense, that's really silly. After all, there are no known military threats to our borders in North America.
Whether or not you are looking at "offensive" vs. "defensive" activity, the analytic point is secondary to the primary issue and the issue is whether or not Israel should intervene once our forces are in action.
I say no.