1. The September 11th, 2001 terrorist attacks in the United States caused major disruptions to global supply chains. The closing of US airspace and borders immediately following the attacks grounded planes and delayed truck shipments at borders. Many manufacturers experienced materials shortages as supply chains were interrupted. Stricter security protocols were implemented throughout supply chains as a result. 2. The COVID-19 pandemic also caused widespread supply chain issues globally. Lockdowns reduced production and shipping. This caused surpluses of some goods and shortages of others as demand and supply became mismatched. For example, toilet paper shortages occurred early in the pandemic as demand rose quickly. Businesses experienced shortages of particular goods that relied on international shipping