Some days ago, it was reported that Hezbollah sleeper cells were being activated in Canada. There's no particular reason for Hezbollah to limit target recon operations to Canada. The purported reason is revenge for the February assassination of a Hezbollah leader, for which Hezbollah blames Israel. However, there may be deeper motivating reasons, given that one expert claimed that such attacks would alienate supporters.
Today, in response to alleged Israeli military exercises, Iran warned that it would deliver a devastating response to any attack. Iran's Revolutionary Guard provides assistance to Hezbollah. Given the timing, it's conceivable that Iran may employ Hezbollah as a proxy to retaliate against Israeli interests on a global scale should Israel launch an air strike. Similarly, it's conceivable that Iran may consider extending such operations to retaliating against American interests globally should the USA launch air strikes.