Hong Kong ( CNN ) -- Less than six months ago , eurozone watchers had been predicting the breakup of the 17-member bloc of nations as the euro plunged to a 25-month low against the U.S. dollar last July . Even as recently as November , Warren Buffett , the famed CEO of Berkshire Hathaway , said of the eurozone 's future that `` it 's hard to tell exactly how it comes out . '' But since then , the euro has appreciated nearly 11 % as its member countries battled to contain sovereign debt crises , rising unemployment and social unrest . The euro now stands at a 13-month high against the greenback . And flying in the face of last year 's critics , former European Central Bank chief Jean-Claude Trichet told CNN 's Nina dos Santos that the euro `` was never about to collapse '' and that its viability as a currency is solid . `` The euro as a currency has never been put in question , '' asserted Trichet , while at the same time admitting the euro area 's financial stability and credit worthiness had been tested . As for the euro , he said it `` is certainly reliable and credible . '' Yet , the euro 's gains over the past seven months is a mixed blessing . Arguments have long-existed for and against a stronger currency . Appreciation means investors are more confident in the euro but eurozone exports become more expensive when sold overseas ; devaluation makes the bloc 's exports more competitive globally , which many eurozone officials would prefer . But if the world 's major economies devalued their currencies to make exports more competitive and to spur their economies to growth again , it would be chaos , says Trichet . `` If the reasoning is the same in all constituencies you have nothing but ... a 'beggar-thy-neighbor ' policy which is a recipe for catastrophe . '' That catastrophe could take the form of an all-out currency war . And this week , the world 's leading banks called on the G20 group of richest nations to avoid such an outcome . `` We believe major central banks should focus on enhancing their cooperation ... to guide market expectations and thus help avoid a disorderly interest rate adjustment process and undue exchange rate volatility , '' the Institute of International Finance wrote in a letter to Russian Finance Minister Anton Siluanov , who is chairing the G20 finance minister 's meeting later this week . But with the eurozone in recession for the second time in four years , the desire to devalue the euro may be strong . The European Central Bank in December cut its 2013 growth forecast , with a best-case growth rate scenario of only 0.3 % . `` It is no time for complacency , '' warned Trichet who added that the central banks of the United States , Japan and Europe as well as their private sectors should get their `` house ( s ) in order . ''
Former European Central Bank chief says euro was never going to collapse . In 2012 , critics predicted at least partial breakup of 17-member eurozone . Euro plunged to 25-month low against U.S. dollar in July 2012 . Score: 6