When Iraq invaded Kuwait 27 years ago this month, the S&P 500 fell 1.1 percent, and was down 9.3 percent 20 days later.
But after yesterday's action on the index, "we can possibly rule out the threat of nuclear war as a catalyst", said Jim Reid, strategist, and Jeff Cai, research analyst.
"North Korea doesn't seem like they're going to back down and the USA has also made a very strong stance this time". The U.S. dollar was down 0.3% at 110.01 yen which hurt the share prices of motor-vehicle makers, technology companies and banks.
The Dow and S&P 500 inched higher on the day but they both posted their largest weekly percentage drops since late March.
The last time the S&P closed down more than 1 percent was May 17.
The yen is often sought in times of geopolitical tension, partly because Japan has a big current account surplus, and it being the world's biggest creditor nation, there is an assumption Japanese investors may repatriate their foreign holdings in times of heightened global uncertainty.
The FTSE 100 fell by more than 100 points as global investors continued to act on North Korea-related jitters.
The London market endured heavy losses on Friday as America's stand-off with North Korea inspired another round of selling.
On Friday basic resource stocks dropped 2.6 percent to a month low as Chinese base metal prices fell.
On the economic front, data is expected to show that US consumer prices likely rose in July after being unchanged the prior month.
"The market is interpreting it as lowering the odds of the Fed raising rates in December", said Keith Lerner, chief market strategist at SunTrust Advisory Services in Atlanta.
"North Korea is being used as a reason to sell Japanese stocks, just as it was used yesterday in the United States", said Soichiro Monji from Daiwa SB Investments in Tokyo.
The dollar index, which tracks the greenback against six rival currencies, was down 0.17 percent to 93.391.
The 30-year bond US30YT=RR last rose 5/32 in price to yield 2.8107 percent, from 2.818 percent late on Wednesday.
"After today's data and commentary from Dudley, if we see even a near-miss on CPI tomorrow, I think the dollar has got quite a bit of room to sell off", Sweeting said.
Crude oil prices fell on Thursday, on concerns of lingering global oversupply as Russian Federation considered a future output resumption and OPEC boosted its July production numbers.