In the meantime, the Army was bullish about managing the implications of delays to introducing Ajax and its ability to meet its NATO commitments.15 However, it has had to plan a series of operational compromises to achieve this, such as continuing to use Challenger 2 tanks and ageing Warrior armoured infantry vehicles, which the Department plans to withdraw from service shortly. The Army also acknowledged it would need careful planning to maintain the right number of frontline Challenger tanks because it must take Challenger 2 out of the line to upgrade them to Challenger 3.16 Furthermore, keeping old capabilities in service adds to wider affordability pressures, which the Army will need to manage within its equipment programme.17 Planning and programme management shortcomings