What obstacles did Zhang Qian face on his expedition?

Zhang Qian faced numerous obstacles during his expeditions, including harsh geographic conditions such as deserts and mountains, which made travel difficult. He encountered hostile tribes and political instability in the regions he traversed, complicating his mission. Additionally, he faced logistical challenges, such as limited supplies and the necessity of negotiating safe passage through unfamiliar territories. Despite these difficulties, his journeys were pivotal in establishing trade routes between China and Central Asia.