No Latin American countries have nukes, and despite spending most of the 19th century beating the stuffing out of each other on a regular basis [1] there's been almost zero inter-state violence since WW2.
Modern Russia is also nowhere near the unstoppable conventional military juggernaut that the Cold War-era USSR was.
You'd also have to consider the likelihood of one getting through your laser defences, and what the cost of protecting your country with these would be.
If you have a 99% chance of stopping a missile, but your adversary has tens or hundreds of thousands of missiles to fire at you, those aren't great odds.
Plus in a pinch, modern societies could probably come up with some fairly hideous deterrent weapons that didn't require missile delivery.
That’s a good point, and in fact probability of error doesn’t even need to come into play. If you can destroy 10 missiles per second with probability 1, then you have a 0% chance of stopping 11 missiles at once. Massive simplifications here but the point stands. Scale matters.
Modern Russia is also nowhere near the unstoppable conventional military juggernaut that the Cold War-era USSR was.
[1] https://en.wikipedia.org/wiki/List_of_conflicts_in_South_Ame...