Wall street puts its doubts aside as the dowjones finally hits 20,000. Plus, tax wars. Can Brexit Britain and trumps us beat the likes of ireland at their own game and lure back the multinationals and their billions . Welcome to World Business report. Im sally bundock. We will be checking how markets are doing in asia injust a moment. We start in the us where President Trump has been provoking more controversy over his plans to wall off mexico. Meanwhile, traders at the New York Stock Exchange are cheering the trump effect. Heres what they have been celebrating the Dow Jones Industrial average of top us shares ended here, finally closing above 20,000 points For The First Time in its isi year history. Its a huge psychological milestone for traders, the dow has now risen some 9. 5 since the election in november, one of its biggest rallies on record. It got within one point of 20,000 back on january sixth before nerves caused the rally to fizzle out. But since President Trumps inauguratio