"t is most often attributed to Julius Caesar who used the strategy in his conquest of Gaul"
I find several places in which your analogy to Julius Caesar and his strategy in Gaul breaks down:
1. The Celtic tribes of Gual did not outnumber the Romans 3 or 4 to 1
2. Rome itself was never under threat of Gaul
3. Rome controlled vast sums of wealth from which to sustain a large army on foreign soil
4. Divide and conquer may be a decent temporary tactic for us but not a winning tactic like it was for Caesar due to the fact that it is a strategy that takes a long period of time... which growing nuclear threat makes untenable
I have no data and neither do you, but I'll bet they did when the Roman army first went into Gaul.
3. Rome controlled vast sums of wealth from which to sustain a large army on foreign soil
I disagree. Relatively speaking the US is in the same position. You can bet that if the US were ever seriously threatened there would be plenty of money to defend it.
4. Divide and conquer may be a decent temporary tactic for us but not a winning tactic like it was for Caesar due to the fact that it is a strategy that takes a long period of time... which growing nuclear threat makes untenable
The nuclear threat from Islamists has made our new friendship with Pakistan all that more a piece of diplomatic genius. Mutually Assured Destruction (MAD) has historically extended time constants for agression so I would again disagree with your counter.
Divide and Conquer is what the Muslims are doing to us.
First Europe and then us.
Between those here who understand the existential nature of this threat and know it must be fought to win, and those who believe we can moderate countries like Pakistan and the UAE.
"2. Rome itself was never under threat of Gaul"
Yes. The Romans did not welcome the Gaulists into Rome for coin.