From what I understand Apple's investment in Samsung was pretty insignificant, $100M. You have to remember that Samsung routinely spends billions to build / upgrade their manufacturing plants - or $41B in 2012 alone.
It's more like 4.6% last year. Apple's component sales accounts for only $7B of Samsung Electronic's $150B revenue in 2011 - not a fatal hit, especially considering 40%-50% growth in Samsung mobile's revenue/profit.
Samsung has been making mobile devices for at least a full decade longer than Apple and has sizable 3G/LTE patent pools. Samsung wasn't even a major player in the US smartphone market until last year - HTC was. I'm not quite sure how Apple is going to work around this - there is really nobody out there big or reliable to enough to meet Apple's demand.
Well, that's not technically correct - considering that the US too has been artificially devaluing the currency for a while (US dollar index was 120 in 2000, now it's 78). But it's politically much convenient to blame foreigners, immigrants or other marginalized groups for all their economic/social ills.