Now, Russia has been forced to import supplies as angry citizens queue for fuel.Diesel is the primary fuel choice for agriculture, and price shifts like those above have a huge impact on planting decisions as margins are whittled to the bone.In addition, the Ukraine attacks have also disrupted global wheat shipments.Between them, Russia and Ukraine account for almost a third of the global wheat trade But severe drought has rendered the waterway impassable.Those same extreme weather conditions led to a sharp reduction in yields from European producers, particularly France and Germany.When Washington was shrouded in Canadian brushfire smoke during the FIFA World Cup, it should have been a stark warning to even those in the White House that the global climate was changing.Together, the US and Canada account for between 25 and 30 per cent of global wheat exports.America, however, is on track for its worst wheat harvest in more than half a century, with the Great Plains, scene of the great US dust bowl during the 1930s depression, again experiencing a severe and debilitating drought.Given bumper crops in recent years helped build reserves, global wheat prices, while edging up, have yet to respond to the impending supply shortfalls.And war of a different kind has also contributed to the disrupted global food trade.Donald Trump's strong-arm trade tactics forced many smaller nations to strike purchase agreements with the US for wheat supplies.Bangladesh, Indonesia and Israel all agreed to preference US wheat purchases over other suppliers as part of an offset agreement to avoid tariffs on their own exports.But the arrangement means they will need to accept whatever price US wheat is trading at rather than being able to purchase on the open market