4. In cases of significant operational difficulties in the application of this Article impairing the safeguard of essential security or defence policy interests, Member States may temporarily suspend such application on condition that they inform without delay the Commission and the other Member States thereof. Following the introduction of a temporary suspension, adjustments to the rules adopted under paragraph 3 may be developed for the airspace under the responsibility of the Member State concerned. The temporary suspension and any such adjustments shall be lifted when those operational difficulties cease.