Shares were initially subdued amid disappointing export data from the UK and Germany but rose as weak US employment figures eased fears the Federal Reserve's quantitative easing programme was nearing its end.
However, Vladimir Putin's hint that Russia would back Syria in the face of any US attacks heightened fears over a Middle East showdown and sent the FTSE 100 Index into negative territory before it rallied again to end 14.9 points up at 6547.3.
France's Cac 40 and Germany's Dax also finished higher while the Dow Jones Industrial Average in New York was in positive territory at the close in London.
The pound was up marginally on the greenback amid indications that US stimulus had more time left to run, at $1.56 while it was flat against the single currency at €1.19.
Dominating the session had been the release of American employment data, which showed a below-expected 169,000 jobs were added in August, while revisions to July's figures showed gains were much less than previously thought.
Meanwhile a fall in the headline unemployment rate was undercut by the fact that because many have now stopped looking for a job, the proportion of those working or looking for work is at its lowest level for 35 years.
The data pushed shares up as the prospect of the US Federal Reserve starting to taper its multi-billion stimulus package later this month started to fade.
Alpari analyst Craig Erlam said fluctuating interpretations of the figures had sparked mayhem in the financial markets, adding that it would be "difficult to justify tapering" in the light of the disappointing data. Later, reported comments from one Fed official that he could be persuaded to support tapering dampened hopes, while Mr Putin's remarks added to jitters.
CMC Markets analyst Michael Hewson said later comments by Barack Obama that it was important not to "jump the gun" on a decision eased market fears.
The economic uncertainty put some pressure on commodity stocks, with miner Fresnillo down 17p to 1264p and Randgold Resources off 66p at 4989p.
B&Q owner Kingfisher slipped a little, off 0.6p to 406.4p, after Morgan Stanley downgraded the stock with a price target of 300p.
Meanwhile, Tullow Oil topped the risers board after it announced a discovery in Norway's Arctic region. Shares gained more than 3%, or 37p, to 1070p.
The biggest risers on the FTSE 100 were Tullow Oil, Meggitt up 12p to 545p, Antofagasta climbing 18p to 899p and Burberry up 30p to 1600p. The biggest fallers on the were Sage Group, down 6.3p to 345.8p, Fresnillo, Randgold Resources and Astrazeneca down 26p to 3117.5p.